         return self._encodeBody(params: processedParams)
     }
     
-    private func _processingMultipartBody(params: [String: Any]) -> [(String, String)] {
+    func _processingMultipartBody(params: [String: Any]) -> [(String, String)] {
         let flatParams = self._flat(params: params)
         if flatParams.count == 0 {
             return []

        return self._encodeMultipartBody(params: processedParams)
    }
    
    private func _insert(params: inout [(String, String)], key: String, value: String) {
        if let index = params.firstIndex(where: { return $0.0 == key }) {
            params[index] = (key, value)
        } else {

        return result
    }

    func _encode(key: String) -> String {
        var string = key
        if self.trimArraySymbolsUrlParams == true {
            if let regexp = try? NSRegularExpression(pattern: "\\[[0-9]+\\]", options: []) {
