code: func (c *RefCount) DecRef() {
  	n := atomic.AddInt32(&c.ref, -1)
  	tracebackEvent(c, int(n), decRefEvent)
  
  	if n < 0 {
  		err := fmt.Errorf("negative ref count, ref=%d", n)
  		panicRef(c, err)
  	}
  }
docs: // DecRef decrements the reference count to this entity.