Revert "Implemented , , and ."
Revert "Implemented , , and ."

This reverts commit 1fe91a780a31c622adf433c6df2b01e7c4fc3ce3.

morrisonlevi/PHP-Datastructures,ircmaxell/PHP-Datastructures,morrisonlevi/Ardent,JeroenDeDauw/Ardent