code: func (e *Encbuf) PutHash(h hash.Hash) {
  	h.Reset()
  	_, err := h.Write(e.B)
  	if err != nil {
  		panic(err) // The CRC32 implementation does not error
  	}
  	e.B = h.Sum(e.B)
  }
docs: // PutHash appends a hash over the buffers current contents to the buffer.