AddressSetView getRestrictedAddressSet() {
		return mergeEngine.getRestrictedAddressSet();
	}
Gets the address set being used to restrict the resulting difference set
that is reported by getting the differences. This address set is 
effectively a view port into the differences address set.
@return the address set used to restrict the differences.
The addresses in this set are derived from the p1 program.
Ghidra/Features/ProgramDiff/src/main/java/ghidra/app/plugin/core/diff/DiffController.java