-(NSArray *)fetchSFMediaItemWithPredicateFormat:(NSString *)format, ...;

/**
 * Return an array with SFMediaItems found in the local database for the given predicate.
 */
-(NSArray *)fetchSFMediaItemWithPredicateFormat:(NSString *)format, ... {
    
    NSFetchRequest *request = [[NSFetchRequest alloc] init];
	NSEntityDescription *entity = [NSEntityDescription entityForName:@"SFMediaItem" inManagedObjectContext:self.managedObjectContext];
	[request setEntity:entity];
    
	va_list args;
	va_start(args, format);
	NSPredicate *predicate = [NSPredicate predicateWithFormat:format arguments:args];
	va_end(args); 
	[request setPredicate:predicate];
    
	
	NSError *error = nil;
	NSArray *array = [self.managedObjectContext executeFetchRequest:request error:&error];
	if (error != nil) {
		NSLog(@"ERROR FETCHING DATA FROM DB FOR PREDICATE");
	}
	
    [request release];
	
	return array;
}

-(NSUInteger)countSFMediaItemWithPredicateFormat:(NSString *)format, ...;

/**
 * Return how many SFMediaItems are found in the local database for the given predicate.
 */
-(NSUInteger)countSFMediaItemWithPredicateFormat:(NSString *)format, ... {
    
	NSFetchRequest *request = [[NSFetchRequest alloc] init];
	NSEntityDescription *entity = [NSEntityDescription entityForName:@"SFMediaItem" inManagedObjectContext:self.managedObjectContext];
	[request setEntity:entity];
	
	va_list args;
	va_start(args, format);
	NSPredicate *predicate = [NSPredicate predicateWithFormat:format arguments:args];
	va_end(args); 
	[request setPredicate:predicate];
	
	NSError *error = nil;
	NSUInteger count = [self.managedObjectContext countForFetchRequest:request error:&error];
	if (error != nil) {
        NSLog(@"ERROR COUNT DATA FROM DB FOR PREDICATE");
    }
	
    [request release];
    
	return count;
}