类继承多接口

<?php 
interface iUsb1 {
public function test1();
}
interface iUsb2{
public function test2();
}
interface iUsb3 extends iUsb1,iUsb2{
public function test3();
}
class A implements iUsb3{
public function test1(){
echo '<br> test1()';


}
public function test2(){
echo '<br> test2()';


}
public function test3(){
echo '<br> test3()';
}
}
?>