code: func (*ConfigurationManager) getKeyName(fieldName string, fieldTagName reflect.StructTag) string {
  	tagName := fieldTagName.Get(configClientTag)
  	if tagName == "-" {
  		return ignoreField
  	} else if tagName == "" {
  		return toSnake(fieldName)
  	} else if tagName == ",inline" {
  		tag := strings.Split(tagName, ",")
  		tagName = tag[1]
  		return tagName
  	}
  
  	return tagName
  }
docs: // get key from tag