This method returns TRUE on custom wrappers by default if you don't implement the stream_lock() method inside the wrapper : http://php.net/manual/en/streamwrapper.stream-lock.php
(PHP 5 >= 5.3.0, PHP 7, PHP 8)
stream_supports_lock — Indica si el flujo soporta bloqueo
Indica si el flujo soporta bloqueo a través de flock().
stream
El flujo a comprobar.
Devuelve true
en caso de éxito o false
en caso de error.
This method returns TRUE on custom wrappers by default if you don't implement the stream_lock() method inside the wrapper : http://php.net/manual/en/streamwrapper.stream-lock.php