     func handleMappingError<T: Decodable>(with decoder: JSONDecoder = JSONDecoder(),
                                           handler: @escaping ParameterClosure<T>) -> Completable {
             return self.do(onError: { error in
-                guard let mappingModel = try error.handleMappingError(with: decoder) as T? else {
+                guard let errorModel = try error.handleMappingError(with: decoder) as T? else {
                     return
                 }
 
-                handler(mappingModel)
+                handler(errorModel)
             })
     }
 }

    ///
    /// - Parameter decoder: json decoder to decode response data
    /// - Returns: optional target object
    func handleMappingError<T: Decodable>(with decoder: JSONDecoder = JSONDecoder()) throws -> T? {
        guard let self = requestError, case .mapping(_, let response) = self else {
            return nil

    func handleMappingError<T: Decodable>(with decoder: JSONDecoder = JSONDecoder(),
                                          handler: @escaping ParameterClosure<T>) -> Observable<E> {
            return self.do(onError: { error in
                guard let errorModel = try error.handleMappingError(with: decoder) as T? else {
                    return
                }

                handler(errorModel)
            })
    }
}
