code: public int getNumberOfSuccessors() {
  
  		int numberOfSuccessors = 0;
  
  		for (int i = 0; i < this.outputGates.length; ++i) {
  			numberOfSuccessors += this.outputGates[i].getNumberOfEdges();
  		}
  
  		return numberOfSuccessors;
  	}
docs: Returns the number of successors, i.e. the number of vertices
  this vertex is connected to.
  
  @return the number of successors