exec_streamer_builder.go
func (e *execStreamerBuilder) OnStarted(onStarted func(*StartedDetails)) ExecStreamerBuilder {
	e.d.OnStarted = onStarted
	return e
}
func (e *execStreamerBuilder) OnStarted(onStarted func(*StartedDetails)) ExecStreamerBuilder {
	e.d.OnStarted = onStarted
	return e
}
//DebugInfo adds debug info to be printed out when errors occur