code: func (m *InMem) List(ctx context.Context, prefix string) ([]string, error) {
  	m.Lock()
  	defer m.Unlock()
  
  	keys := make([]string, 0, len(m.data))
  	for k := range m.data {
  		keys = append(keys, k)
  	}
  	sort.Strings(keys)
  	return keys, nil
  }
docs: // List shows all values