@staticmethod
def tokens_end_update(tokens, end=None):
    """Update the end of tokens accordinly to the start of the next one into the tokens list.

    Paramaters
    ----------
    tokens: list

    Returns
    -------
    tokens: list
    """
    if len(tokens) > 0:
        for k, tok in enumerate(tokens[:-1]):
            tok['end_next'] = tokens[k + 1]['start']
        if end is not None:
            tokens[-1]['end_next'] = end
    return tokens
