php多重接口的实现方法

<?php   interface staff_i1 //接口1   {    function setID($id);    function getID();   }     interface staff_i2 //接口2   {    function setName($name);    function getName();   }       class staff implements staff_i1, staff_i2 //接口的实现   {    private $id;    private $name;    function setID($id)    {      $this->id = $id;    }    function getID()     {      return $this->id;    }    function setName($name)     {      $this->name = $name;    }    function getName()     {      return $this->name;    }    function otherFunc()    {     echo "Test";    }   } ?>