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"; 
   } 
  } 
?>