@Override
	public boolean add(Edge e) {
		double wt = getWeight(e);
		boolean returnValue = super.add(e);
		if (returnValue) {
			setWeight(e, defaultValue);
		}
		else {
			setWeight(e, wt + defaultValue);
		}
		return true;
	}
Add an edge. If successful (i.e. that edge does not already appear
in the graph), set the weight to the default value
@return true if edge added succesfuly.
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/WeightedDigraph.java