private Object doCall(Invoker invoker,Object receiver,String method,Object... args) throws Throwable {
  return filterReturnValue(invoker.call(receiver,method,filterArgs(args)));
}

private Object doCall ( Invoker invoker , Object receiver , String method , Object ... args ) throws Throwable { return filterReturnValue ( invoker . call ( receiver , method , filterArgs ( args ) ) ) ; }
performs an actual call to the given method on the given receiver object using the given invoker . the arguments and return value are filtered according to the sandbox , but the receiver is not .
