Fetches user's data and returns it wrapped in a Grruser object.

def Get(self):
    """Fetches user's data and returns it wrapped in a Grruser object."""

    args = user_management_pb2.ApiGetGrrUserArgs(username=self.username)
    data = self._context.SendRequest("GetGrrUser", args)
    return GrrUser(data=data, context=self._context)