code: protected String safeGetQuickReplyPayload(MessageEnvelope envelope) {
  		if (envelope != null && envelope.getMessage() != null
  				&& envelope.getMessage().getQuickReply() != null
  				&& envelope.getMessage().getQuickReply().getPayload() != null) {
  			return envelope.getMessage().getQuickReply().getPayload();
  		}
  
  		return "";
  	}
docs: Retrieves a quick reply payload from an envelope. It never returns null.
  
  @param envelope
  the message envelope.
  @return the text message if found or an empty String otherwise. It never
  returns null.