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: serversentevents.go
    path of file: ./repos/coder/codersdk
    
    the code of the file until where you have to start completion: package codersdk

import (
	"bufio"
	"context"
	"fmt"
	"io"
	"strings"

	"golang.org/x/xerrors"

	"github.com/coder/coder/v2/coderd/tracing"
)

type ServerSentEvent struct {
	Type ServerSentEventType `json:"type"`
	Data interface{}         `json:"data"`
}

type ServerSentEventType string

const (
	ServerSentEventTypePing  ServerSentEventType = "ping"
	ServerSentEventTypeData  ServerSentEventType = "data"
	ServerSentEventTypeError ServerSentEventType = "error"
)

func ServerSentEventReader(ctx context.Context, rc io.ReadCloser) func() (*ServerSentEvent, error) {
	_, span := tracing.StartSpan(ctx)
	defer span.End()

	reader := bufio.NewReader(rc)
	nextLineValue := func(prefix string) ([]byte, error) {
		var (
			line string
			err  error
		)
		for {
			line, err = reader.ReadStrin
    
func ServerSentEventReader(ctx context.Context, rc io.ReadCloser) func() (*ServerSentEvent, error) {
	_, span := tracing.StartSpan(ctx)
	defer span.End()

	reader := bufio.NewReader(rc)
	nextLineValue := func(prefix string) ([]byte, error) {
		var (
			line string
			err  error
		)
		for {
			line, err = reader.ReadString('\n')
			if err != nil {
				return nil, xerrors.Errorf("reading next string: %w", err)
			}
			if strings.TrimSpace(line) != "" {
				break
			}
		}

		if !strings.HasPrefix(line, fmt.Sprintf("%s: ", prefix)) {
			return nil, xerrors.Errorf("expecting %s prefix, got: %s", prefix, line)
		}
		s := strings.TrimPrefix(line, fmt.Sprintf("%s: ", prefix))
		s = strings.TrimSpace(s)
		return []byte(s), nil
	}

	nextEvent := func() (*ServerSentEvent, error) {
		for {
			t, err := nextLineValue("event")
			if err != nil {
				return nil, xerrors.Errorf("reading next line value: %w", err)
			}

			switch ServerSentEventType(t) {
			case ServerSentEventTypePing:
				return &ServerSentEvent{
					Type: ServerSentEventTypePing,
				}, nil
			case ServerSentEventTypeData:
				d, err := nextLineValue("data")
				if err != nil {
					return nil, xerrors.Errorf("reading next line value: %w", err)
				}

				return &ServerSentEvent{
					Type: ServerSentEventTypeData,
					Data: d,
				}, nil
			case ServerSentEventTypeError:
				d, err := nextLineValue("data")
				if err != nil {
					return nil, xerrors.Errorf("reading next line value: %w", err)
				}

				return &ServerSentEvent{
					Type: ServerSentEventTypeError,
					Data: d,
				}, nil
			default:
				return nil, xerrors.Errorf("unknown event type: %s", t)
			}
		}
	}

	return nextEvent
}