        self.id   = json["id"].stringValue
    }
}

open class MarkerParam: ParameterEncodable {
    let action:   Marker.Action
    let itemType: Marker.ItemType
    let itemIds:  [String]
    init(action: Marker.Action, itemType: Marker.ItemType, itemIds:[String]) {
        self.action   = action
        self.itemType = itemType
        self.itemIds  = itemIds
    }

    open func toParameters() -> [String : Any] {