code: func (c *RefCount) IncWrites() {
  	tracebackEvent(c, c.NumRef(), incWritesEvent)
  	n := atomic.AddInt32(&c.writes, 1)
  	ref := c.NumRef()
  
  	if n > 0 && ref < 1 {
  		err := fmt.Errorf("write after free: writes=%d, ref=%d", n, ref)
  		panicRef(c, err)
  	}
  
  	if n > 1 {
  		err := fmt.Errorf("double write: writes=%d, ref=%d", n, ref)
  		panicRef(c, err)
  	}
  }
docs: // IncWrites increments the writes count to this entity.