setMessage = function setMessage(msg) {
        if (msg !== currentMessage) {
          element.html(msg);
          currentMessage = msg;
        }
      }
I am the messages directive for description and error message handling

@param  {object} $injector I am the Angular injector for optional dependencies
@param  {object} sfErrorMessage I contain the interpolation function for messages

@return {object} I am the message directive API