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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 _tls_decrypt(alg, c):
 """ Provided with a TLSCiphertext instance c, and a stream or block cipher alg, the function decrypts c.data and returns a newly created TLSPlaintext. """

    p = TLSPlaintext()
    p.type = c.type
    p.version = c.version
    p.data = alg.decrypt(c.data)
    p.len = len(p.data)
    return p