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: images_test.go
    path of file: ./repos/sliver/util/encoders
    
    the code of the file until where you have to start completion: package encoders

/*
	Sliver 
    
func TestPNG(t *testing.T) {
	pngEncoder := new(PNGEncoder)
	for _, test := range imageTests {
		buf, _ := pngEncoder.Encode(test.Input)
		decodeOutput, err := pngEncoder.Decode(buf)
		if err != nil {
			t.Errorf("png decode returned error: %q", err)
		}
		if !bytes.Equal(test.Input, decodeOutput) {
			t.Errorf("png Decode(img) => %q, expected %q", decodeOutput, test.Input)
		}
	}
}