code: func (c *Conn) ClearCache(clearId bool, clearBloom bool, args map[string]interface{}, indices ...string) (ExtendedStatus, error) {
  	var retval ExtendedStatus
  	var clearCacheUrl string
  	if len(indices) > 0 {
  		clearCacheUrl = fmt.Sprintf("/%s/_cache/clear", strings.Join(indices, ","))
  
  	} else {
  		clearCacheUrl = fmt.Sprintf("/_cache/clear")
  	}
  
  	body, err := c.DoCommand("POST", clearCacheUrl, args, nil)
  	if err != nil {
  		return retval, err
  	}
  	if err == nil {
  		// marshall into json
  		jsonErr := json.Unmarshal(body, &retval)
  		if jsonErr != nil {
  			return retval, jsonErr
  		}
  	}
  	return retval, err
  }
docs: // ClearCache allows to clear either all caches or specific cached associated with one ore more indices.
  // see http://www.elasticsearch.org/guide/reference/api/admin-indices-clearcache/