private Structure getParentStructureFromClassStructures(String parentName)
			throws CancelledException {

		List<Structure> parentStructures = new ArrayList<>();
		for (Structure classStructure : classStructures) {
			monitor.checkCancelled();

			if (classStructure.getName().equals(parentName)) {
				parentStructures.add(classStructure);
			}

		}
		if (parentStructures.size() == 1) {
			return parentStructures.get(0);
		}
		return null;

	}
Attempts to get the parent structure from the list of class structures
@param parentName the name of the parent
@return the parent structure if there is only one with the given name, else returns null
@throws CancelledException if cancelled
Ghidra/Features/Base/ghidra_scripts/GraphClassesScript.java