Custom handler with context

[LaiArturs]

Hi!

I would like to implement a custom Handler with Play function that uses some context values. Currently when setting up Speech struct the handler seams to be copied and not passed as a pointer. Meaning if I change value in my handler later in code the change is not seen by Speech struct.

Example of my handler implementation for illustrative purposes:

type MyHandler struct {
	myValue		string
}

func (handler *MyHandler) Play(fileName string) error {
	log.Println(handler.myValue)
	return nil
}