// +build ignore,OMIT package drawer import ( "math" "testing" ) type TestFunc func(float64) float64 func (f TestFunc) Eval(x float64) float64 { return f(x) } var ( ident = TestFunc(func(x float64) float64 { return x }) sin = TestFunc(math.Sin) ) func TestDraw_Ident(t *testing.T) { m := Draw(ident) // Verify obtained image. // END OMIT t.Error(m.ColorModel()) }