public static function register()
    {
        self::$root = null;
        if (true === self::$registered) {
            return;
        }

        if (@stream_wrapper_register(vfsStream::SCHEME, __CLASS__) === false) {
            throw new vfsStreamException('A handler has already been registered for the ' . vfsStream::SCHEME . ' protocol.');
        }

        self::$registered = true;
    }
public static function register()
    {
        self::$root = null;
        if (true === self::$registered) {
            return;
        }

        if (@stream_wrapper_register(vfsStream::SCHEME, __CLASS__) === false) {
            throw new vfsStreamException('A handler has already been registered for the ' . vfsStream::SCHEME . ' protocol.');
        }

        self::$registered = true;
    }
public static function register ( ) { self :: $ root = null ; if ( true === self :: $ registered ) { return ; } if ( @ stream_wrapper_register ( vfsStream :: SCHEME , __CLASS__ ) === false ) { throw new vfsStreamException ( 'A handler has already been registered for the ' . vfsStream :: SCHEME . ' protocol.' ) ; } self :: $ registered = true ; }
method to register the stream wrapper

Please be aware that a call to this method will reset the root element
to null.
If the stream is already registered the method returns silently. If there
is already another stream wrapper registered for the scheme used by
vfsStream a vfsStreamException will be thrown.

@throws  vfsStreamException
method to register the stream wrapper