code: func (d *diagnosticsCollector) Set(name string, value interface{}) {
  	switch v := value.(type) {
  	case string:
  		if v == "" {
  			// Do not set empty string
  			return
  		}
  	}
  	d.mu.Lock()
  	defer d.mu.Unlock()
  	d.metrics[name] = value
  }
docs: // Set adds a key value metric.