human
Complete the below
def coerce_versions(a, b):

    ''''Convert both a and b to the \'greatest\' type between them, in this order:
    Version < VersionRange < VersionList
    This is used to simplify comparison operations below so that we\'re always
    comparing things that are of the same type.'
    '''
 ... What is a the Python code you requested?
assistant
#Here is the Python code you requested.
    order = (Version, VersionRange, VersionList)
    (ta, tb) = (type(a), type(b))
    def check_type(t):
        if (t not in order):
            raise TypeError(('coerce_versions    cannot    be    called    on    %s' % t))
    check_type(ta)
    check_type(tb)
    if (ta == tb):
        return (a, b)
    elif (order.index(ta) > order.index(tb)):
        if (ta == VersionRange):
            return (a, VersionRange(b, b))
        else:
            return (a, VersionList([b]))
    elif (tb == VersionRange):
        return (VersionRange(a, a), b)
    else:
        return (VersionList([a]), b)