code: public static Function<Message, MailMessage> toMailMessage() {
  		return new Function<Message, MailMessage>() {
  			@Override
  			public MailMessage apply(final Message input) {
  				return MailMessage.fromMessage(input);
  			}
  		};
  	}
docs: Creates a function that transforms a {@link Message} object to a {@link MailMessage} object.
  
  @return the function