Removes and returns a RTMMessage from self._inbox

        Args:
            block(bool): if True block until a RTMMessage is available,
                         else it will return None when self._inbox is empty
            timeout(int): it blocks at most timeout seconds

        Returns:
            RTMMessage if self._inbox is not empty, else None

def get_message(self, block=False, timeout=None):
        """Removes and returns a RTMMessage from self._inbox

        Args:
            block(bool): if True block until a RTMMessage is available,
                         else it will return None when self._inbox is empty
            timeout(int): it blocks at most timeout seconds

        Returns:
            RTMMessage if self._inbox is not empty, else None
        """
        try:
            message = self._inbox.get(block=block, timeout=timeout)
            return message
        except Exception:
            return None