Can upload new account image

lib/models/account_image_settings.dart

@@ -0,0 +1,21 @@
+import 'package:flutter/widgets.dart';
+
+/// Account image settings
+///
+/// @author Pierre Hubert
+
+enum AccountImageVisibilityLevels { EVERYONE, COMUNIC_USERS, FRIENDS_ONLY }
+
+class AccountImageSettings {
+  final bool hasImage;
+  final String imageURL;
+  final AccountImageVisibilityLevels visibility;
+
+  const AccountImageSettings({
+    @required this.hasImage,
+    @required this.imageURL,
+    @required this.visibility,
+  })  : assert(hasImage != null),
+        assert(imageURL != null),
+        assert(visibility != null);
+}

lib/models/api_request.dart

@@ -22,14 +22,25 @@ class APIRequest {
     if (this.args == null) this.args = Map();
   }
 
-  void addString(String name, String value) => args[name] = value;
+  APIRequest addString(String name, String value) {
+    args[name] = value;
+    return this;
+  }
 
-  void addInt(String name, int value) => args[name] = value.toString();
+  APIRequest addInt(String name, int value) {
+    args[name] = value.toString();
+    return this;
+  }
 
-  void addBool(String name, bool value) =>
-      args[name] = value ? "true" : "false";
+  APIRequest addBool(String name, bool value) {
+    args[name] = value ? "true" : "false";
+    return this;
+  }
 
-  void addFile(String name, File file) => files[name] = file;
+  APIRequest addFile(String name, File file) {
+    files[name] = file;
+    return this;
+  }
 
   void addArgs(Map<String, String> newArgs) => args.addAll(newArgs);