Method isEmpty

library/src/main/java/com/sanders/db/DBProxy.java:664–669

集合NULL判断 @param collection @return

(Collection collection)

     * @return
     */
    private boolean isEmpty(Collection collection) {
        if (collection == null || collection.isEmpty()) {
            return true;
        }
        return false;
    }

    /**
     * 返回当前数据库打开关闭计数