NSObject+Error.m

@implementation NSObject (Error)

- (void)removeObserver:(NSObject * _Nonnull)observer forKeyPath:(NSString * _Nonnull)keyPath error:(NSError * _Nullable __autoreleasing * _Nullable)error {
    @try {
        [self removeObserver:observer forKeyPath:keyPath];
    } @catch (NSException *exception) {
        NSMutableDictionary *userInfo = nil;
        if (exception.userInfo == nil) {
            userInfo = [NSMutableDictionary dictionaryWithCapacity:0];
        } else {
            userInfo = exception.userInfo.mutableCopy;
        }
        userInfo[NSLocalizedDescriptionKey] = exception.reason;
        *error = [NSError errorWithDomain:exception.name code:-9999 userInfo:userInfo];
    }
}

@end