Xcode12Beta: Value of type 'CBLArray' has no subscripts

@protocol Model <NSObject>

- (NSInteger) objectAtIndexedSubscript: (NSUInteger)index;

- (void) functionality;

@end

@interface ModelObject : NSObject <Model>

// This will avoid the error::

// - (NSInteger) objectAtIndexedSubscript: (NSUInteger)index

@end

@implementation ModelObject

- (NSInteger) objectAtIndexedSubscript: (NSUInteger)index {

    return 0;

}

- (void) functionality {

    NSLog(@"called functionality");

}

@end

class SwiftModel {

    func someFunction(obj: ModelObject) {

        // works fine

        obj.functionality()

        // error: Value of type 'ModelObject' has no subscripts

        print(obj[0])

    }

}