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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 tointerval(s):
 """ If string, then convert to an interval; otherwise just return the input """

    if isinstance(s, basestring):
        m = coord_re.search(s)
        if m.group('strand'):
            return pybedtools.create_interval_from_list([
                m.group('chrom'),
                m.group('start'),
                m.group('stop'),
                '.',
                '0',
                m.group('strand')])
        else:
            return pybedtools.create_interval_from_list([
                m.group('chrom'),
                m.group('start'),
                m.group('stop'),
            ])
    return s