Exemplo de como usar method overloading no PHP

Poly.php

<?php 

class Poly {
    
    public function __call($name, $arg) {
        
        if ($name == 'test') {
            switch(count($arg)) {
                case 0:
                    return 'Test without argument';
                    break;
                case 1:
                    return 'Test with an argument ' . $arg[0];
            }
        }
        
    }
    
}

$poly = new Poly();

print $poly->test() . PHP_EOL;
print $poly->test('Look at me!') . PHP_EOL;