def replace_timestamp(matchobj):
    """
    helper function that keep any times that are in "times" list

    :param matchobj: Is used to compare to the timestamps in times to select which timestamps to remove
    :return: returns empty line if timestamp not found. If found returns the timestamp to be included in document
    """

    times = ['00:15:00', '00:30:00', '00:45:00', '01:00:00', '01:15:00''01:30:00', '01:45:00', '02:00:00',
             '02:15:00' '02:30:00', '02:45:00', ]

    if matchobj.group(0) in times:
        print(f"Found time: {matchobj.group(0)}")
        new_time = f"<p> {matchobj.group(0)} </p>"
        return new_time
    else:
        return ''