private void addBackEdge(V u, V v) {
		Set<V> set = blockedBackEdgesMap.get(u);
		if (set == null) {
			set = new HashSet<>();
			blockedBackEdgesMap.put(u, set);
		}
		set.add(v);
	}
Finds the circuits in the graph passed at construction time.

@param uniqueCircuits true signals to return only unique circuits, where no two 
       circuits will contain the same vertex
@param monitor the task monitor
@throws CancelledException if the monitor is cancelled
Ghidra/Framework/Graph/src/main/java/ghidra/graph/algo/JohnsonCircuitsAlgorithm.java