code: func NewWithWriter(w statsdWriter) (*Client, error) {
  	client := &Client{writer: w, SkipErrors: false}
  
  	// Inject DD_ENTITY_ID as a constant tag if found
  	entityID := os.Getenv(entityIDEnvName)
  	if entityID != "" {
  		entityTag := fmt.Sprintf("%s:%s", entityIDTagName, entityID)
  		client.Tags = append(client.Tags, entityTag)
  	}
  
  	return client, nil
  }
docs: // NewWithWriter creates a new Client with given writer. Writer is a
  // io.WriteCloser + SetWriteTimeout(time.Duration) error