driver.go
func (c HubConfig) GetInt(key string, defval int) int {
	val, ok := c[key]
	if ok {
		i, ok := val.(int)
		if ok {
			return i
		}
		s := c.GetString(key, "")
		if len(s) > 0 {
			i, err := strconv.Atoi(s)
			if err != nil {
				// TODO handling error on app level
				return defval
			}
			return i
		}
	}
	return defval
}
func (c HubConfig) GetInt(key string, defval int) int {
	val, ok := c[key]
	if ok {
		i, ok := val.(int)
		if ok {
			return i
		}
		s := c.GetString(key, "")
		if len(s) > 0 {
			i, err := strconv.Atoi(s)
			if err != nil {
				// TODO handling error on app level
				return defval
			}
			return i
		}
	}
	return defval
}
// GetInt property.