def setVertex(self, vertexId, vertex=None):
        if self.getNumVertices()==0 and not self.vertexExists(vertexId):
            super(DictTree, self).setVertex(vertexId, vertex)
        elif self.vertexExists(vertexId):
            super(DictTree, self).setVertex(vertexId, vertex)
        else:
            raise RuntimeError("Can only set a new vertex in an empty tree: " + str(vertexId))
Worker calls this method to finish a batch/future.
dataset/ETHPy150Open charanpald/APGL/apgl/graph/DictTree.py/DictTree.setVertex--crossover with--dataset/ETHPy150Open membase/membase-cli/pump.py/Sink.future_done