(PHP 5 >= 5.1.2, PHP 7) Tells if the file is a directory

(PHP 5 >= 5.1.2, PHP 7) Try all registered __autoload() function to load the requested class

(PHP 5 >= 5.1.0, PHP 7) Returns if an iterator can be created fot the current entry.

(PHP 5 >= 5.1.0, PHP 7) Detach an observer

(PHP 5 >= 5.3.0, PHP 7) Returns whether the requested index exists

(PHP 5 >= 5.4.0, PHP 7) Serializes the storage

(PHP 5 >= 5.2.2, PHP 7) Gets the target of a link

(PHP 5 >= 5.3.0, PHP 7) Rewind iterator back to the start (no-op)

(PHP 5 >= 5.3.0, PHP 7) Extracts a node from top of the heap and sift up.

(PHP 5 >= 5.3.0, PHP 7) Move to previous entry