// Copyright 2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Code generated by protoc-gen-go_gapic. DO NOT EDIT.

package logging

import (
	"context"
	"time"

	loggingpb "cloud.google.com/go/logging/apiv2/loggingpb"
	"cloud.google.com/go/longrunning"
	longrunningpb "cloud.google.com/go/longrunning/autogen/longrunningpb"
	gax "github.com/googleapis/gax-go/v2"
	"google.golang.org/api/iterator"
	monitoredrespb "google.golang.org/genproto/googleapis/api/monitoredres"
)

// CopyLogEntriesOperation manages a long-running operation from CopyLogEntries.
type CopyLogEntriesOperation struct {
	lro      *longrunning.Operation
	pollPath string
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *CopyLogEntriesOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*loggingpb.CopyLogEntriesResponse, error) {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	var resp loggingpb.CopyLogEntriesResponse
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *CopyLogEntriesOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*loggingpb.CopyLogEntriesResponse, error) {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	var resp loggingpb.CopyLogEntriesResponse
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *CopyLogEntriesOperation) Metadata() (*loggingpb.CopyLogEntriesMetadata, error) {
	var meta loggingpb.CopyLogEntriesMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *CopyLogEntriesOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *CopyLogEntriesOperation) Name() string {
	return op.lro.Name()
}

// CreateBucketAsyncOperation manages a long-running operation from CreateBucketAsync.
type CreateBucketAsyncOperation struct {
	lro      *longrunning.Operation
	pollPath string
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *CreateBucketAsyncOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*loggingpb.LogBucket, error) {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	var resp loggingpb.LogBucket
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *CreateBucketAsyncOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*loggingpb.LogBucket, error) {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	var resp loggingpb.LogBucket
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *CreateBucketAsyncOperation) Metadata() (*loggingpb.BucketMetadata, error) {
	var meta loggingpb.BucketMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *CreateBucketAsyncOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *CreateBucketAsyncOperation) Name() string {
	return op.lro.Name()
}

// CreateLinkOperation manages a long-running operation from CreateLink.
type CreateLinkOperation struct {
	lro      *longrunning.Operation
	pollPath string
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *CreateLinkOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*loggingpb.Link, error) {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	var resp loggingpb.Link
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *CreateLinkOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*loggingpb.Link, error) {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	var resp loggingpb.Link
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *CreateLinkOperation) Metadata() (*loggingpb.LinkMetadata, error) {
	var meta loggingpb.LinkMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *CreateLinkOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *CreateLinkOperation) Name() string {
	return op.lro.Name()
}

// DeleteLinkOperation manages a long-running operation from DeleteLink.
type DeleteLinkOperation struct {
	lro      *longrunning.Operation
	pollPath string
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *DeleteLinkOperation) Wait(ctx context.Context, opts ...gax.CallOption) error {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	return op.lro.WaitWithInterval(ctx, nil, time.Minute, opts...)
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *DeleteLinkOperation) Poll(ctx context.Context, opts ...gax.CallOption) error {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	return op.lro.Poll(ctx, nil, opts...)
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *DeleteLinkOperation) Metadata() (*loggingpb.LinkMetadata, error) {
	var meta loggingpb.LinkMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *DeleteLinkOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *DeleteLinkOperation) Name() string {
	return op.lro.Name()
}

// UpdateBucketAsyncOperation manages a long-running operation from UpdateBucketAsync.
type UpdateBucketAsyncOperation struct {
	lro      *longrunning.Operation
	pollPath string
}

// Wait blocks until the long-running operation is completed, returning the response and any errors encountered.
//
// See documentation of Poll for error-handling information.
func (op *UpdateBucketAsyncOperation) Wait(ctx context.Context, opts ...gax.CallOption) (*loggingpb.LogBucket, error) {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	var resp loggingpb.LogBucket
	if err := op.lro.WaitWithInterval(ctx, &resp, time.Minute, opts...); err != nil {
		return nil, err
	}
	return &resp, nil
}

// Poll fetches the latest state of the long-running operation.
//
// Poll also fetches the latest metadata, which can be retrieved by Metadata.
//
// If Poll fails, the error is returned and op is unmodified. If Poll succeeds and
// the operation has completed with failure, the error is returned and op.Done will return true.
// If Poll succeeds and the operation has completed successfully,
// op.Done will return true, and the response of the operation is returned.
// If Poll succeeds and the operation has not completed, the returned response and error are both nil.
func (op *UpdateBucketAsyncOperation) Poll(ctx context.Context, opts ...gax.CallOption) (*loggingpb.LogBucket, error) {
	opts = append([]gax.CallOption{gax.WithPath(op.pollPath)}, opts...)
	var resp loggingpb.LogBucket
	if err := op.lro.Poll(ctx, &resp, opts...); err != nil {
		return nil, err
	}
	if !op.Done() {
		return nil, nil
	}
	return &resp, nil
}

// Metadata returns metadata associated with the long-running operation.
// Metadata itself does not contact the server, but Poll does.
// To get the latest metadata, call this method after a successful call to Poll.
// If the metadata is not available, the returned metadata and error are both nil.
func (op *UpdateBucketAsyncOperation) Metadata() (*loggingpb.BucketMetadata, error) {
	var meta loggingpb.BucketMetadata
	if err := op.lro.Metadata(&meta); err == longrunning.ErrNoMetadata {
		return nil, nil
	} else if err != nil {
		return nil, err
	}
	return &meta, nil
}

// Done reports whether the long-running operation has completed.
func (op *UpdateBucketAsyncOperation) Done() bool {
	return op.lro.Done()
}

// Name returns the name of the long-running operation.
// The name is assigned by the server and is unique within the service from which the operation is created.
func (op *UpdateBucketAsyncOperation) Name() string {
	return op.lro.Name()
}

// LinkIterator manages a stream of *loggingpb.Link.
type LinkIterator struct {
	items    []*loggingpb.Link
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*loggingpb.Link, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *LinkIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *LinkIterator) Next() (*loggingpb.Link, error) {
	var item *loggingpb.Link
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *LinkIterator) bufLen() int {
	return len(it.items)
}

func (it *LinkIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// LogBucketIterator manages a stream of *loggingpb.LogBucket.
type LogBucketIterator struct {
	items    []*loggingpb.LogBucket
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*loggingpb.LogBucket, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *LogBucketIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *LogBucketIterator) Next() (*loggingpb.LogBucket, error) {
	var item *loggingpb.LogBucket
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *LogBucketIterator) bufLen() int {
	return len(it.items)
}

func (it *LogBucketIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// LogEntryIterator manages a stream of *loggingpb.LogEntry.
type LogEntryIterator struct {
	items    []*loggingpb.LogEntry
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*loggingpb.LogEntry, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *LogEntryIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *LogEntryIterator) Next() (*loggingpb.LogEntry, error) {
	var item *loggingpb.LogEntry
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *LogEntryIterator) bufLen() int {
	return len(it.items)
}

func (it *LogEntryIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// LogExclusionIterator manages a stream of *loggingpb.LogExclusion.
type LogExclusionIterator struct {
	items    []*loggingpb.LogExclusion
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*loggingpb.LogExclusion, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *LogExclusionIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *LogExclusionIterator) Next() (*loggingpb.LogExclusion, error) {
	var item *loggingpb.LogExclusion
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *LogExclusionIterator) bufLen() int {
	return len(it.items)
}

func (it *LogExclusionIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// LogMetricIterator manages a stream of *loggingpb.LogMetric.
type LogMetricIterator struct {
	items    []*loggingpb.LogMetric
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*loggingpb.LogMetric, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *LogMetricIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *LogMetricIterator) Next() (*loggingpb.LogMetric, error) {
	var item *loggingpb.LogMetric
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *LogMetricIterator) bufLen() int {
	return len(it.items)
}

func (it *LogMetricIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// LogSinkIterator manages a stream of *loggingpb.LogSink.
type LogSinkIterator struct {
	items    []*loggingpb.LogSink
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*loggingpb.LogSink, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *LogSinkIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *LogSinkIterator) Next() (*loggingpb.LogSink, error) {
	var item *loggingpb.LogSink
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *LogSinkIterator) bufLen() int {
	return len(it.items)
}

func (it *LogSinkIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// LogViewIterator manages a stream of *loggingpb.LogView.
type LogViewIterator struct {
	items    []*loggingpb.LogView
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*loggingpb.LogView, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *LogViewIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *LogViewIterator) Next() (*loggingpb.LogView, error) {
	var item *loggingpb.LogView
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *LogViewIterator) bufLen() int {
	return len(it.items)
}

func (it *LogViewIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// MonitoredResourceDescriptorIterator manages a stream of *monitoredrespb.MonitoredResourceDescriptor.
type MonitoredResourceDescriptorIterator struct {
	items    []*monitoredrespb.MonitoredResourceDescriptor
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*monitoredrespb.MonitoredResourceDescriptor, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *MonitoredResourceDescriptorIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *MonitoredResourceDescriptorIterator) Next() (*monitoredrespb.MonitoredResourceDescriptor, error) {
	var item *monitoredrespb.MonitoredResourceDescriptor
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *MonitoredResourceDescriptorIterator) bufLen() int {
	return len(it.items)
}

func (it *MonitoredResourceDescriptorIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// OperationIterator manages a stream of *longrunningpb.Operation.
type OperationIterator struct {
	items    []*longrunningpb.Operation
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*longrunningpb.Operation, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *OperationIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *OperationIterator) Next() (*longrunningpb.Operation, error) {
	var item *longrunningpb.Operation
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *OperationIterator) bufLen() int {
	return len(it.items)
}

func (it *OperationIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// StringIterator manages a stream of string.
type StringIterator struct {
	items    []string
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []string, nextPageToken string, err error)
}

// PageInfo supports pagination. See the [google.golang.org/api/iterator] package for details.
func (it *StringIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *StringIterator) Next() (string, error) {
	var item string
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *StringIterator) bufLen() int {
	return len(it.items)
}

func (it *StringIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}
