Liskov 1: PHP method overwriting

PHP-method-overwriting.php

<?php
class ClasseBase
{
    public function metodo($a) { } // um parâmetro
}

class SubClasse extends ClasseBase
{
    public function metodo($a, $b) { } // dois parâmetros
}

// PHP Strict standards:
// Declaration of SubClasse::metodo() should be compatible with ClasseBase::metodo($a)