<?php
$set = new \Ds\Set([1, 2, 3]);
var_dump($set->contains(1)); // true
var_dump($set->contains(1, 2)); // true
var_dump($set->contains(...[1, 2])); // true
var_dump($set->contains("1")); // false
var_dump($set->contains(...[1, 2, 3, 4])); // false
var_dump($set->contains(...[])); // true
?>
The above example will output
something similar to:
bool(true)
bool(true)
bool(true)
bool(false)
bool(false)
bool(true)