<?php

$b = new stdClass;

$b->method = function($x) {
    var_dump( $x);
};

$b->method->__invoke('dads');   // string(4) "dads"
$b->method('dads');             // PHP Fatal error: Call to undefined method stdClass::method() in php shell code on line 1
($b->method)('dads');           // PHP Parse error: syntax error, unexpected '(' in php shell code on line 1