@Override
			public void modifyLatest(ProgramDB program) {
				// Change the Latest program which will also be used for Result program.
				try {
					FunctionManager functionManager = program.getFunctionManager();
					Function thunkFunction =
						functionManager.getFunctionAt(addr(program, THUNK_A_ENTRY));
					Function referredToFunction =
						functionManager.getFunctionAt(addr(program, FUNCTION_2));
					assertNotNull(thunkFunction);
					assertNotNull(referredToFunction);
					thunkFunction.setThunkedFunction(referredToFunction);
				}
				catch (Exception e) {
					Assert.fail(e.getMessage());
				}
			}
Test the Diff of thunk functions.
Ghidra/Features/Base/src/test.slow/java/ghidra/program/util/ExternalFunctionDiffTest.java