code: public function callMethodInWrappedInst($method, $args)
      {
          $i = $this->getWrappedInst();
          if (method_exists($i, $method)) {
              return call_user_method_array($method, $i, $args);
          }
          throw new UnknownMethodException('Calling unknown method: ' . get_class($i) . "::$method()");
      }
docs: Calls the method in the wrapped instance
  
  This method is used internally in order to call a method
  of the wrapped interface. Usually this function is called
  by the magic function __call if the Wrapper does implement
  the called method.
  
  @param type $method
  @param type $args