def get_link_enjambment(previous_token, next_token):
    """
    Checks if a link enjambment exists between two lines
    :param previous_token: The word before a newline character
    :param next_token: The word before a newline character
    :return: Link type or None if not found
    """
    if next_token.n_rights > 0 or (next_token.head == previous_token.head):
        if ((previous_token.dep_ in ('ROOT', 'nsubj')
             and previous_token is next_token.head)
                or (next_token.nbor().is_ancestor(previous_token))):
            return [previous_token.pos_, next_token.pos_]
    return None