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: colorful_test.go
    path of file: ./repos/trojan-go/log/golog/colorful
    
    the code of the file until where you have to start completion: // The color engine for the go-log library
// Copyright (c) 2017 Fadhli Dzil Ikram
//
// Test file

package colorful

import (
	"testing"

	. "github.com/smartystreets/goconvey/convey"
    
func TestColorBuffer(t *testing.T) {
	Convey("Given empty color buffer and test data", t, func() {
		var cb ColorBuffer
		var result buffer.Buffer

		// Add color to the result buffer
		result.Append(colorRed)
		result.Append(colorGreen)
		result.Append(colorOrange)
		result.Append(colorBlue)
		result.Append(colorPurple)
		result.Append(colorCyan)
		result.Append(colorGray)
		result.Append(colorOff)

		Convey("When appended with color", func() {
			cb.Red()
			cb.Green()
			cb.Orange()
			cb.Blue()
			cb.Purple()
			cb.Cyan()
			cb.Gray()
			cb.Off()

			Convey("It should have same content with the test data", func() {
				So(result.Bytes(), ShouldResemble, cb.Bytes())
			})
		})
	})
}