'Retrieve a child or child\'s child of this path.
@param segments: A sequence of path segments as L{str} instances.
@return: A L{FilePath} constructed by looking up the C{segments[0]}
child of this path, the C{segments[1]} child of that path, and so
on.
@since: 10.2'

def descendant(self, segments):

    path = self
    for name in segments:
        path = path.child(name)
    return path
