code: func compressedTxOutSize(amount uint64, pkScript []byte) int {
  	return serializeSizeVLQ(compressTxOutAmount(amount)) +
  		compressedScriptSize(pkScript)
  }
docs: // -----------------------------------------------------------------------------
  // Compressed transaction outputs consist of an amount and a public key script
  // both compressed using the domain specific compression algorithms previously
  // described.
  //
  // The serialized format is:
  //
  //   <compressed amount><compressed script>
  //
  //   Field                 Type     Size
  //     compressed amount   VLQ      variable
  //     compressed script   []byte   variable
  // -----------------------------------------------------------------------------
  // compressedTxOutSize returns the number of bytes the passed transaction output
  // fields would take when encoded with the format described above.