code: func (p *Namespaces) Clone() *Namespaces {
  	if !p.Safe {
  		p.mu.RLock()
  		defer p.mu.RUnlock()
  	}
  	p2 := Namespaces{
  		prefixes: make(map[string]string, len(p.prefixes)),
  	}
  	for pref, ns := range p.prefixes {
  		p2.prefixes[pref] = ns
  	}
  	return &p2
  }
docs: // Clone makes a copy of namespaces list.