code: public void addVertex(final AbstractJobOutputVertex outputVertex) {
  
  		if (!outputVertices.containsKey(outputVertex.getID())) {
  			outputVertices.put(outputVertex.getID(), outputVertex);
  		}
  	}
docs: Adds a new output vertex to the job graph if it is not already included.
  
  @param outputVertex
  the new output vertex to be added