[OBJC] type object is not cast correctly

Description

Type "object" in swagger.json is cast as NSObject which produces a bug

Swagger-codegen version

2.2.2-SNAPSHOT

Swagger declaration file content or url

Command line used for generation

java -jar modules/swagger-codegen-cli/target/swagger-codegen-cli.jar generate 
-i http://127.0.0.1:9000/swagger.json 
-l objc 
-o samples/client/CLIENT 
-c config.json

Steps to reproduce

JSONModel crash after HTTP request is sent

Related issues

Suggest a Fix

Restlet studio manages this type correctly with the Class ASKFields:

ASKFields.h

#import "ASKRepresentation.h"
@interface ASKFields : ASKRepresentation
+ (instancetype)representation;
@end

ASKFields.m

#import "ASKFields.h"
@implementation ASKFields
+ (instancetype)representation {
    return [[self alloc] init];
}

- (NSString *)description {
    NSMutableString *result = [NSMutableString string];
    return result;
}

#pragma mark - Dictionary Representation
- (NSDictionary *)toDictionary {
    return @{
            };
}
+ (instancetype)fromDictionary:(NSDictionary *)aDictionary {
    if (aDictionary == nil) {
        return nil;
    }
    ASKFields *result = [self representation];
    return result;
}
@end

Reproduce the generation command with the supplied swagger.json URL using the objc generator and inspect the generated client under samples/client/CLIENT. Start from the generated model handling the Swagger type "object" and the JSONModel crash after the request. Done means object values are represented correctly and the generated client no longer crashes.