'Return this L{FilePath} in L{bytes}-mode.
@param encoding: The encoding to use if coercing to L{bytes}. If none is
given, L{sys.getfilesystemencoding} is used.
@return: L{bytes} mode L{FilePath}'

def asBytesMode(self, encoding=None):

    if (type(self.path) == unicode):
        return self.clonePath(self._asBytesPath(encoding=encoding))
    return self
