You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: backends.go
    path of file: ./repos/plumber/backends
    
    the code of the file until where you have to start completion: package backends

import (
	"context"

	"github.com/pkg/errors"

	"github.com/streamdal/plumber/backends/activemq"
	"github.com/streamdal/plumber/backends/awskinesis"
	"github.com/streamdal/plumber/backends/awssns"
	"github.com/streamdal/plumber/backends/awssqs"
	azureEventhub "github.com/streamdal/plumber/backends/azure-eventhub"
	azureServicebus "github.com/streamdal/plumber/backends/azure-servicebus"
	"github.com/streamdal/plumber/backends/cdcmongo"
	"github.com/streamdal/plumber/backends/cdcpostgres"
	"github.com/streamdal/plumber/backends/gcppubsub"
	"github.com/streamdal/plumber/backends/kafka"
	kubemqQueue "github.com/streamdal/plumber/backends/kubemq-queue"
	"github.com/streamdal/plumber/backends/memphis"
	"github.com/streamdal/plumber/backends/mqtt"
	"github.com/streamdal/plumber/backends/nats"
	natsJetstream "github.com/streamdal/plumber/backends/nats-jetstream"
	natsStreaming "github.com/streamdal/plumber/backends/nats-streaming"
	"github.com/streamdal/plumber/backends/nsq"
	"github.com/streamdal/plumber/backends/pulsar"
	rabbitStreams "github.com/streamdal/plumber/backends/rabbit-streams"
	"github.com/streamdal/plumber/backends/rabbitmq"
	"github.com/streamdal/plumber/backends/rpubsub"
	"github.com/streamdal/plumber/backends/rstreams"
	"github.com/streamdal/plumber/tunnel"

	"github.com/batchcorp/plumber-schemas/build/go/protos/opts"
	"github.com/batchcorp/plumber-schemas/build/go/protos/records"
)

// Backend is the interface that all backends implement; the interface is used
// for facilitating all CLI and server functionality in plumber.
// NOTE: Most backends do not support _some_ part of the interface - in those
// cases the methods will either return types.NotImplementedErr or
// types.UnsupportedFeatureErr.
type Back
    
func New(connOpts *opts.ConnectionOptions) (Backend, error) {
	var be Backend
	var err error

	switch connOpts.Conn.(type) {
	case *opts.ConnectionOptions_Kafka:
		be, err = kafka.New(connOpts)
	case *opts.ConnectionOptions_ActiveMq:
		be, err = activemq.New(connOpts)
	case *opts.ConnectionOptions_AwsSqs:
		be, err = awssqs.New(connOpts)
	case *opts.ConnectionOptions_AwsSns:
		be, err = awssns.New(connOpts)
	case *opts.ConnectionOptions_AzureServiceBus:
		be, err = azureServicebus.New(connOpts)
	case *opts.ConnectionOptions_AzureEventHub:
		be, err = azureEventhub.New(connOpts)
	case *opts.ConnectionOptions_Mqtt:
		be, err = mqtt.New(connOpts)
	case *opts.ConnectionOptions_GcpPubsub:
		be, err = gcppubsub.New(connOpts)
	case *opts.ConnectionOptions_Nats:
		be, err = nats.New(connOpts)
	case *opts.ConnectionOptions_NatsStreaming:
		be, err = natsStreaming.New(connOpts)
	case *opts.ConnectionOptions_Nsq:
		be, err = nsq.New(connOpts)
	case *opts.ConnectionOptions_Pulsar:
		be, err = pulsar.New(connOpts)
	case *opts.ConnectionOptions_Rabbit:
		be, err = rabbitmq.New(connOpts)
	case *opts.ConnectionOptions_RabbitStreams:
		be, err = rabbitStreams.New(connOpts)
	case *opts.ConnectionOptions_RedisPubsub:
		be, err = rpubsub.New(connOpts)
	case *opts.ConnectionOptions_RedisStreams:
		be, err = rstreams.New(connOpts)
	case *opts.ConnectionOptions_Mongo:
		be, err = cdcmongo.New(connOpts)
	case *opts.ConnectionOptions_KubemqQueue:
		be, err = kubemqQueue.New(connOpts)
	case *opts.ConnectionOptions_Postgres:
		be, err = cdcpostgres.New(connOpts)
	case *opts.ConnectionOptions_NatsJetstream:
		be, err = natsJetstream.New(connOpts)
	case *opts.ConnectionOptions_AwsKinesis:
		be, err = awskinesis.New(connOpts)
	case *opts.ConnectionOptions_Memphis:
		be, err = memphis.New(connOpts)
	default:
		return nil, errors.New("unknown backend")

	}

	if err != nil {
		return nil, errors.Wrap(err, "unable to instantiate backend")
	}

	return be, nil
}