code: func RegisterPartial(name string, source string) {
  	partialsMutex.Lock()
  	defer partialsMutex.Unlock()
  
  	if partials[name] != nil {
  		panic(fmt.Errorf("Partial already registered: %s", name))
  	}
  
  	partials[name] = newPartial(name, source, nil)
  }
docs: // RegisterPartial registers a global partial. That partial will be available to all templates.