code: func (e Env) Clone() Env {
  	clone := e
  	clone.env = nil
  
  	if len(e.env) > 0 {
  		clone.env = make(map[string]string, len(e.env))
  		for k, v := range e.env {
  			clone.env[k] = v
  		}
  	}
  	return clone
  }
docs: // Clone creates a new Env instance that is identical to, but independent from,
  // e.