public long getModificationCount() {
		return modCount;
	}
Returns the current modification count which is incremented anytime any archive or any
category or datatype it contains is changed in any way. This includes the datatypes in
the current program.
@return the current modification id.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/archive/DataTypeManagerHandler.java