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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _dates(p_word_before_cursor):
 """ Generator for date completion. """

    to_absolute = lambda s: relative_date_to_date(s).isoformat()

    start_value_pos = p_word_before_cursor.find(':') + 1
    value = p_word_before_cursor[start_value_pos:]

    for reldate in date_suggestions():
        if not reldate.startswith(value):
            continue

        yield Completion(reldate, -len(value), display_meta=to_absolute(reldate))