code: func (c *RefCount) DecWrites() {
  	tracebackEvent(c, c.NumRef(), decWritesEvent)
  	n := atomic.AddInt32(&c.writes, -1)
  
  	if ref := c.NumRef(); ref < 1 {
  		err := fmt.Errorf("write finish after free: writes=%d, ref=%d", n, ref)
  		panicRef(c, err)
  	}
  }
docs: // DecWrites decrements the writes count to this entity.