code: func (b *bufferManager) free(d *queue.TxBuffer) {
  	// Find the last buffer in the list.
  	last := d
  	for last.Next != nil {
  		last = last.Next
  	}
  
  	// Push list onto free list.
  	last.Next = b.freeList
  	b.freeList = d
  }
docs: // free returns all buffers in the list to the buffer manager so that they can
  // be reused.