@Override
			public void modifyPrivate(ProgramDB program) {
				ReferenceManager refMgr = program.getReferenceManager();
				Reference[] refs;

				// Change reg ref to mem ref
				refs = refMgr.getReferencesFrom(addr(program, "0x10018a6"), 0);
				assertEquals(1, refs.length);
				refMgr.delete(refs[0]);
				try {
					refMgr.addExternalReference(addr(program, "0x10018a6"), "USER32.DLL",
						"printf", addr(program, "0x01234567"), SourceType.USER_DEFINED, 0,
						RefType.DATA);
				}
				catch (DuplicateNameException e) {
					Assert.fail(e.getMessage());
				}
				catch (InvalidInputException e) {
					Assert.fail(e.getMessage());
				}
			}
Test the merge of the versioned program's listing.
Ghidra/Features/Base/src/test.slow/java/ghidra/app/merge/listing/RefMergerRegTest.java