b::y PHP Method

    function y()
    {
        self::definedInParent();
        self::definedInParentParent();
        self::undefined();
        self::definedinStatic();
        self::$pdefinedInParent;
        self::$pdefinedInParentParent;
        self::$pundefined;
        self::$pdefinedinStatic;
    }

 function __construct()
 {
     a::y();
     b::y();
     c::y();
     d::y();
     a::$x;
     b::$x;
     c::$x;
     d::$x;
     a::$xpr;
     b::$xpr;
     c::$xpr;
     d::$xpr;
 }