code: func (msg *MsgCFilter) BtcDecode(r io.Reader, pver uint32, _ MessageEncoding) error {
  	// Read filter type
  	err := readElement(r, &msg.FilterType)
  	if err != nil {
  		return err
  	}
  
  	// Read the hash of the filter's block
  	err = readElement(r, &msg.BlockHash)
  	if err != nil {
  		return err
  	}
  
  	// Read filter data
  	msg.Data, err = ReadVarBytes(r, pver, MaxCFilterDataSize,
  		"cfilter data")
  	return err
  }
docs: // BtcDecode decodes r using the bitcoin protocol encoding into the receiver.
  // This is part of the Message interface implementation.