<?php
 
abstract class AbstractShit
{
	private $color;
	private $weight; // В килограммах
	private $smell;
 
	abstract function eat();
	public function smearYourself() { /* Можно ли задать тут реализацию по умолчанию? */ }
}
 
class Shit extends AbstractShit
{
	public function eat()
	{
		echo 'Ням, ням, ням!';
	}
	public function smearYouself()
	{
		echo 'Уфф, уфф!';
	}
}
 
$shit = new Shit;
$shit->color = 'Темно-зеленый';
$shit->weight = 0.5;
$shit->smell = 'Как земля';
$shit->eat();

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