private boolean treeStructureChanged(long treeID) {

		ProgramModule sourceRoot = myListing.getRootModule(treeID);
		ProgramModule destRoot = resultListing.getRootModule(treeID);
		ProgramModule originalRoot = originalProgram.getListing().getRootModule(treeID);
		long sourceModNumber = sourceRoot.getModificationNumber();
		return (destRoot != null && destRoot.getModificationNumber() != sourceModNumber) ||
			(originalRoot != null && originalRoot.getModificationNumber() != sourceModNumber);

	}
Tree structure changed if the modification numbers on trees do not
match, OR, modification number of original is not the same as the
modification on the source tree.
@param treeID ID of source root
@return whether the structure changed
Ghidra/Features/Base/src/main/java/ghidra/app/merge/tree/ProgramTreeMergeManager.java