docs: def getEdges(self, personID, nextStageIndex=0):
          """getEdges(string, int) -> list(string)
  
          Returns a list of all edges in the nth next stage.
          For waiting stages this is a single edge
          For walking stages this is the complete route
          For driving stages this is [origin, destination]
  
          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_EDGES, personID, 1 + 4)
          self._connection._string += struct.pack("!Bi",
                                                  tc.TYPE_INTEGER, nextStageIndex)
          return self._connection._checkResult(tc.CMD_GET_PERSON_VARIABLE,
                                               tc.VAR_EDGES, personID).readStringList()