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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 _get_reference_position(isomir):
 """ Liftover from isomir to reference mature """

    mut = isomir.split(":")[1]
    if mut == "0":
        return mut
    nt, pos = _parse_mut(mut)
    trim5 = isomir.split(":")[-2]
    off = -1 * len(trim5)
    if trim5.islower():
        off = len(trim5)
    if trim5 == "NA" or trim5 == "0":
        off = 0
    # print(isomir)
    # print([mut, pos, off, nt])
    return "%s%s" % (pos + off, nt)