def trim(self, len_):
        """Return a copy of the version, possibly with less tokens.

        Args:
            len_ (int): New version length. If >= current length, an
                unchanged copy of the version is returned.
        """
        other = Version(None)
        other.tokens = self.tokens[:len_]
        other.seps = self.seps[:len_ - 1]
        return other
Return a copy of the version, possibly with less tokens.

        Args:
            len_ (int): New version length. If >= current length, an
                unchanged copy of the version is returned.