def is_suburi(self, base, test):
        """Check if test is below base in a URI tree

        Both args must be URIs in reduced form.
        """
        if base == test:
            return True
        if base[0] != test[0]:
            return False
        common = posixpath.commonprefix((base[1], test[1]))
        if len(common) == len(base[1]):
            return True
        return False
Check if test is below base in a URI tree

        Both args must be URIs in reduced form.