+ (NSArray *)layoutWithContainers:(NSArray *)containers text:(NSAttributedString *)text range:(NSRange)range {
    if (!containers || !text) return nil;
    if (range.location + range.length > text.length) return nil;
    NSMutableArray *layouts = [NSMutableArray array];
    for (NSUInteger i = 0, max = containers.count; i < max; i++) {
        YYTextContainer *container = containers[i];
        YYTextLayout *layout = [self layoutWithContainer:container text:text range:range];
        if (!layout) return nil;
+       [layouts addObject:layout]; 
        NSInteger length = (NSInteger)range.length - (NSInteger)layout.visibleRange.length;
        if (length <= 0) {
            range.length = 0;
            range.location = text.length;
        } else {
            range.length = length;
            range.location += layout.visibleRange.length;
        }
    }
    return layouts;
}