private void reset() {
		visitedButNotDeletedCount = 0;
		for (DependencyNode node : nodeMap.values()) {
			node.numberOfNodesThatIDependOn = 0;
		}
		for (DependencyNode node : nodeMap.values()) {
			if (node.setOfNodesThatDependOnMe != null) {
				for (DependencyNode child : node.setOfNodesThatDependOnMe) {
					unvisitedIndependentSet.remove(child.value);
					child.numberOfNodesThatIDependOn++;
				}
			}
		}
		unvisitedIndependentSet = getAllIndependentValues();
	}
Checks if this graph has cycles.  Normal processing of this graph will eventually reveal
a cycle and throw an exception at the time it is detected.  This method allows for a 
"fail fast" way to detect cycles.
@return true if cycles exist in the graph.
Ghidra/Framework/Generic/src/main/java/ghidra/util/graph/AbstractDependencyGraph.java