code: func (step *CallFlowSayStep) UnmarshalJSON(data []byte) error {
  	var raw jsonCallFlowSayStep
  	if err := json.Unmarshal(data, &raw); err != nil {
  		return err
  	}
  	*step = CallFlowSayStep{
  		CallFlowStepBase: raw.CallFlowStepBase,
  		Payload:          raw.Options.Payload,
  		Voice:            raw.Options.Voice,
  		Language:         raw.Options.Language,
  		Repeat:           raw.Options.Repeat,
  		IfMachine:        raw.Options.IfMachine,
  		MachineTimeout:   time.Duration(raw.Options.MachineTimeout) * time.Millisecond,
  	}
  	return nil
  }
docs: // UnmarshalJSON implements the json.Unmarshaler interface.