code: func (r *Reader) ReadUint32() uint32 {
  	if r.err != nil {
  		return 0
  	}
  	var n int
  	n, r.err = io.ReadFull(r.rd, r.b[:4])
  	r.cnt += n
  	if r.err != nil {
  		return 0
  	}
  	return binary.LittleEndian.Uint32(r.b[:4])
  }
docs: // ReadUint32 reads and returns an uint32.