______/ \-. _ ______/ \-. _ ______/ \-. _
\.-/ ( o._// \.-/ ( o._// \.-/ ( o._//
| ___ \_/\---' | ___ \_/\---' | ___ \_/\---'
|_|| |_|| |_|| |_|| |_|| |_||
Run php test.php to check the implementation of each linked list.