Decompress c (a TLSCompressed instance) using compression algorithm
    instance alg and return a TLSPlaintext instance.

def _tls_decompress(alg, c):
    """
    Decompress c (a TLSCompressed instance) using compression algorithm
    instance alg and return a TLSPlaintext instance.
    """
    p = TLSPlaintext()
    p.type = c.type
    p.version = c.version
    p.data = alg.decompress(c.data)
    p.len = len(p.data)
    return p