Changed api for getting assets to return and request correct type

lib/src/api/default_api.dart

@@ -3,6 +3,7 @@
 //
 
 import 'dart:async';
+import 'dart:typed_data';
 
 import 'package:dio/dio.dart';
 
@@ -391,9 +392,9 @@ class DefaultApi {
   /// * [onSendProgress] - A [ProgressCallback] that can be used to get the send progress
   /// * [onReceiveProgress] - A [ProgressCallback] that can be used to get the receive progress
   ///
-  /// Returns a [Future] containing a [Response] with a [JsonObject] as data
+  /// Returns a [Future] containing a [Response] with a [Uint8List] as data
   /// Throws [DioError] if API call or serialization fails
-  Future<Response<dynamic>> getAsset({
+  Future<Response<Uint8List>> getAsset({
     required String fid,
     CancelToken? cancelToken,
     ValidateStatus? validateStatus,
@@ -404,9 +405,10 @@ class DefaultApi {
     final _options = Options(
       method: 'GET',
       validateStatus: validateStatus,
+      responseType: ResponseType.bytes,
     );
 
-    final _response = await _dio.request<dynamic>(
+    final _response = await _dio.request<List<int>>(
       _path,
       options: _options,
       cancelToken: cancelToken,
@@ -414,8 +416,20 @@ class DefaultApi {
       onReceiveProgress: onReceiveProgress,
     );
 
-    return Response<dynamic>(
-      data: _response,
+    final respData = _response.data;
+    if (respData == null) {
+      throw DioError(
+        requestOptions: _options.compose(
+          _dio.options,
+          _path,
+        ),
+        type: DioErrorType.unknown,
+        error: 'Response was null',
+      );
+    }
+
+    return Response<Uint8List>(
+      data: Uint8List.fromList(respData),
       headers: _response.headers,
       isRedirect: _response.isRedirect,
       requestOptions: _response.requestOptions,