getStage(string, int) -> int
        Returns the type of the nth next stage
          0 for not-yet-departed
          1 for waiting
          2 for walking
          3 for driving
        nextStageIndex 0 retrieves value for the current stage.
        nextStageIndex must be lower then value of getRemainingStages(personID)

def getStage(self, personID, nextStageIndex=0):
        """getStage(string, int) -> int
        Returns the type of the nth next stage
          0 for not-yet-departed
          1 for waiting
          2 for walking
          3 for driving
        nextStageIndex 0 retrieves value for the current stage.
        nextStageIndex must be lower then value of getRemainingStages(personID)
        """
        self._connection._beginMessage(
            tc.CMD_GET_PERSON_VARIABLE, tc.VAR_STAGE, personID, 1 + 4)
        self._connection._string += struct.pack("!Bi",
                                                tc.TYPE_INTEGER, nextStageIndex)
        return self._connection._checkResult(tc.CMD_GET_PERSON_VARIABLE,
                                             tc.VAR_STAGE, personID).readInt()