code: func (c *threadSafeMap) ListKeys() []string {
  	c.lock.RLock()
  	defer c.lock.RUnlock()
  	list := make([]string, 0, len(c.items))
  	for key := range c.items {
  		list = append(list, key)
  	}
  	return list
  }
docs: // ListKeys returns a list of all the keys of the objects currently
  // in the threadSafeMap.