(PHP 5, PHP 7) Get the current depth of the recursive iteration

(PHP 5 >= 5.1.0, PHP 7) Begin children public

(PHP 5, PHP 7) The current active sub iterator

(PHP 5, PHP 7) Rewind the iterator to the first element of the top level inner iterator

(PHP 5 >= 5.1.0, PHP 7) End children public

(PHP 5 >= 5.1.0, PHP 7) Next element public

(PHP 5 >= 5.1.0, PHP 7) Has children public

(PHP 5 >= 5.1.0, PHP 7) Begin Iteration public

(PHP 5, PHP 7) Move forward to the next element

(PHP 5, PHP 7) Check whether the current position is valid