Returns the absolute location of ``path`` relative to one of
        the ``roots``.

        ``roots`` is the path configured for this `StaticFileHandler`
        (in most cases the ``static_path`` `Application` setting).

def get_absolute_path(cls, roots, path):
        """Returns the absolute location of ``path`` relative to one of
        the ``roots``.

        ``roots`` is the path configured for this `StaticFileHandler`
        (in most cases the ``static_path`` `Application` setting).
        """
        for root in roots:
            abspath = os.path.abspath(os.path.join(root, path))
            if abspath.startswith(root) and os.path.exists(abspath):
                return abspath
        # XXX TODO
        return 'file-not-found'