@Override
	public int hashCode() {
		if (doHashCode) {
			hashCode = vertices.hashCode();
			doHashCode = false;
		}

		return hashCode;
	}
Creates a new group based upon this one, but with the given vertices (and incident edges)
removed. 

@param verticesToRemove the vertices to not include in the new group
@return the new group
Ghidra/Features/FunctionGraph/src/main/java/ghidra/app/plugin/core/functiongraph/graph/vertex/GroupedFunctionGraphVertex.java