<?php class SplMinHeap2 extends SplMinHeap { public function testCompare1() { return parent::compare(); } public function testCompare2() { return parent::compare(1); } public function testCompare3() { return parent::compare(1, 2, 3); } } $h = new SplMinHeap2(); $h->testCompare1(); $h->testCompare2(); $h->testCompare3();