code: func (p *Plugin) Unregister(registryPath string, collector prometheus.Collector) bool {
  	p.Lock()
  	defer p.Unlock()
  
  	reg, found := p.regs[registryPath]
  	if !found {
  		return false
  	}
  	return reg.Unregister(collector)
  }
docs: // Unregister unregisters the given metric. The function
  // returns whether a Collector was unregistered.