@Test
	public void testFunctionRegParamDiff9() throws Exception {

		// added register param in program2

		int transactionID2 = p2.startTransaction("Test Transaction");
		Function function2 = p2.getFunctionManager().getFunctionAt(addr(p2, 0x10048a3));
		Register dr0Reg = p1.getRegister("DR0");
		Variable var2 = new ParameterImpl("variable", new DWordDataType(), dr0Reg, p2);
		function2.addParameter(var2, SourceType.USER_DEFINED);
		p2.endTransaction(transactionID2, true);

		programMerge = new ProgramMergeManager(p1, p2);
		AddressSet diffAs = new AddressSet();
		diffAs.addRange(addr(0x10048a3), addr(0x10048a3));
		programMerge.setDiffFilter(new ProgramDiffFilter(ProgramDiffFilter.FUNCTION_DIFFS));
		programMerge.setMergeFilter(
			new ProgramMergeFilter(ProgramMergeFilter.FUNCTIONS, ProgramMergeFilter.REPLACE));
		assertEquals(diffAs, programMerge.getFilteredDifferences());
		programMerge.merge(diffAs, TaskMonitor.DUMMY);
		assertEquals(new AddressSet(), programMerge.getFilteredDifferences());
	}
Test that ProgramDiff can determine the label differences between
Program1 and Program2.
Ghidra/Features/Base/src/test.slow/java/ghidra/program/util/ProgramMerge1Test.java