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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 from_rdata_list(ttl, rdatas):
 """Create an rdataset with the specified TTL, and with the specified list of rdata objects. @rtype: dns.rdataset.Rdataset object """


    if len(rdatas) == 0:
        raise ValueError("rdata list must not be empty")
    r = None
    for rd in rdatas:
        if r is None:
            r = Rdataset(rd.rdclass, rd.rdtype)
            r.update_ttl(ttl)
            first_time = False
        r.add(rd)
    return r