code: def _tls_compress(alg, p):
      
      c = TLSCompressed()
      c.type = p.type
      c.version = p.version
      c.data = alg.compress(p.data)
      c.len = len(c.data)
      return c
docs: Compress p (a TLSPlaintext instance) using compression algorithm instance
      alg and return a TLSCompressed instance.