Calling a function within a Class method?

example 1
class TestClass{
public function __call($name,$arg){
call_user_func($name,$arg);
}
}
class test {
     public function newTest(){

          function bigTest(){
               echo 'Big Test Here';
          }
          function smallTest(){
               echo 'Small Test Here';
          }

$obj=new TestClass;

return $obj;
     }

}
$rentry=new test;
$rentry->newTest()->bigTest();