BuiltinFunctionRepository { public void register(FunctionResolver resolver) { functionResolverMap.put(resolver.getFunctionName(), resolver); }  void register(FunctionResolver resolver); FunctionImplementation compile(FunctionName functionName, List<Expression> expressions); FunctionBuilder resolve(FunctionSignature functionSignature);  }
@Test void register() { BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap); when(mockfunctionResolver.getFunctionName()).thenReturn(mockFunctionName); repo.register(mockfunctionResolver); verify(mockMap, times(1)).put(mockFunctionName, mockfunctionResolver); }