X::foo PHP Method

    function foo()
    {
        echo __METHOD__;
    }

function test()
{
    $a = X::foo();
    $a();
    $a = Y::foo();
    $a();
    $a = X::bar();
    $a();
    $a = Y::bar();
    $a();
    $x = new X();
    $a = $x->bar();
    $a();
    $x = new Y();
    $a = $x->bar();
    $a();
    $a = X::bar_nonstatic();
    $a();
    $a = Y::bar_nonstatic();
    $a();
    $x = new X();
    $a = $x->bar_nonstatic();
    $a();
    $x = new Y();
    $a = $x->bar_nonstatic();
    $a();
}