public void setDiffFilter(ProgramDiffFilter filter) {
		programDiff.setFilter(filter);
		diffFilter = programDiff.getFilter();
	}
Set the filter that indicates which parts of the Program should be 
diffed.
@param filter the filter indicating the types of differences to be 
determined by this ProgramMerge.
Ghidra/Features/Base/src/main/java/ghidra/program/util/ProgramMergeManager.java