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: frame_output_changelog_test.go
    path of file: ./repos/grafana/pkg/services/live/pipeline
    
    the code of the file until where you have to start completion: package pipeline

import (
	"context"
	"testing"
	"time"

	"github.com/golang/mock/gomock"
	"github.com/grafana/grafana-plugin-sdk-go/data"
	"github.com/stretchr/testify/require"
)

func TestChangeLogOutput_NoPreviousFrame_SingleRow(t *testing.T) {
	mockCtrl := gomock.NewController(t)
	defer mockCtrl.Finish()

	mockStorage := NewMockFrameGetSetter(mockCtrl)

	mockStorage.EXPECT().Get(gomock.Any(), gomock.Any()).DoAndReturn(func(orgID int64, channel string) (*data.Frame, bool, error) {
		return nil, false, nil
	})

	mockStorage.EXPECT().Set(gomock.Any(), gomock.Any(), gomock.Any()).Times(1)

	outputter := NewChangeLogFrameOutput(mockStorage, ChangeLogOutputConfig{
		FieldName: "test",
		Channel:   "stream/test/no_previous_frame",
	})

	f1 := data.NewField("time", nil, make([]time.Time, 1))
	f1.Set(0, time.Now())

	f2 := data.NewField("test", nil, make([]*float
    
func TestChangeLogOutput_NoPreviousFrame_SingleRow(t *testing.T) {
	mockCtrl := gomock.NewController(t)
	defer mockCtrl.Finish()

	mockStorage := NewMockFrameGetSetter(mockCtrl)

	mockStorage.EXPECT().Get(gomock.Any(), gomock.Any()).DoAndReturn(func(orgID int64, channel string) (*data.Frame, bool, error) {
		return nil, false, nil
	})

	mockStorage.EXPECT().Set(gomock.Any(), gomock.Any(), gomock.Any()).Times(1)

	outputter := NewChangeLogFrameOutput(mockStorage, ChangeLogOutputConfig{
		FieldName: "test",
		Channel:   "stream/test/no_previous_frame",
	})

	f1 := data.NewField("time", nil, make([]time.Time, 1))
	f1.Set(0, time.Now())

	f2 := data.NewField("test", nil, make([]*float64, 1))
	f2.SetConcrete(0, 20.0)

	frame := data.NewFrame("test", f1, f2)

	channelFrames, err := outputter.OutputFrame(context.Background(), Vars{}, frame)
	require.NoError(t, err)

	require.Len(t, channelFrames, 1)
	changeFrame := channelFrames[0].Frame
	require.Len(t, changeFrame.Fields, 3)
	var x *float64
	var y = 20.0
	require.Equal(t, x, changeFrame.Fields[1].At(0).(*float64))
	require.Equal(t, &y, changeFrame.Fields[2].At(0))
}