code: func (b *bstream) UnmarshalBinary(bIn []byte) error {
  	buf := bytes.NewReader(bIn)
  	err := binary.Read(buf, binary.BigEndian, &b.count)
  	if err != nil {
  		return err
  	}
  	b.stream = make([]byte, buf.Len())
  	return binary.Read(buf, binary.BigEndian, &b.stream)
  }
docs: // UnmarshalBinary implements the encoding.BinaryUnmarshaler interface