updated readme for func

Author: DavertMik

README.md

@@ -5,7 +5,7 @@ AspectMock is not an ordinary PHP mocking framework.
 With the power of Aspect Oriented programming and the awesome [Go-AOP](https://github.com/lisachenko/go-aop-php) library,
 AspectMock allows you to stub and mock practically anything in your PHP code!
 
-**Documentation** | [Test Doubles Builder](https://github.com/Codeception/AspectMock/blob/master/docs/Test.md) | [ClassProxy](https://github.com/Codeception/AspectMock/blob/master/docs/ClassProxy.md) | [InstanceProxy](https://github.com/Codeception/AspectMock/blob/master/docs/InstanceProxy.md)
+**Documentation** | [Test Doubles Builder](https://github.com/Codeception/AspectMock/blob/master/docs/Test.md) | [ClassProxy](https://github.com/Codeception/AspectMock/blob/master/docs/ClassProxy.md) | [InstanceProxy](https://github.com/Codeception/AspectMock/blob/master/docs/InstanceProxy.md) | [FuncProxy](https://github.com/Codeception/AspectMock/blob/master/docs/FuncProxy.md)
 
 **Stability**: alpha
 
@@ -107,6 +107,15 @@ function testUserCreate()
 ?>
 ```
 
+#### Override even standard PHP functions
+
+``` php
+<?php
+namespace demo;
+test::func('demo', 'time', 'now');
+$this->assertEquals('now', time());
+```
+
 #### Beautifully simple
 
 Only 4 methods are necessary for method call verification and one method to define test doubles: