判断对象是否为空

+ (BOOL)isBlankObject:(__kindof id)object {
    if (!object) {
        return YES;
    }

    if (object == NULL) {
        return YES;
    }
    
    if ([object isEqual:[NSNull null]]) {
        return YES;
    }
    
    if ([object respondsToSelector:@selector(length)]) {
        NSUInteger count = (NSUInteger)[object performSelector:@selector(length)];
        return count == 0;
    }

     ///集合类型
    if ([object respondsToSelector:@selector(count)]) {
        NSUInteger count = (NSUInteger)[object performSelector:@selector(count)];
        return count == 0;
    }
    return NO;
}