Issue5

[YitianChen1996]

Ⅰ. Describe what this PR did

Ⅱ. Does this pull request fix one issue?

#1763

Ⅲ. Describe how you did it

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[pouchrobot]

Thanks for your contribution. 🍻 @YitianChen1996
While we thought PR TITLE could be more specific, longer than 20 chars.
Please edit this PR title instead of opening a new one.
More details, please refer to https://github.com/alibaba/pouch/blob/master/CONTRIBUTING.md

[pouchrobot]

@YitianChen1996 Thanks for your contribution. 🍻
Please sign off in each of your commits.

[pouchrobot]

We found this is your first time to contribute to Pouch, @YitianChen1996
👏 We really appreciate it.
Just remind that you have read the contribution guide: https://github.com/alibaba/pouch/blob/master/CONTRIBUTING.md
If you didn't, you should do that first. If done, welcome again and please enjoy hacking! 🍻

[pouchrobot]

ping @YitianChen1996
Conflict happens after merging a previous commit.
Please rebase the branch against master and push it back again. Thanks a lot.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@afc7a21). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1884   +/-   ##
=========================================
  Coverage          ?   56.59%           
=========================================
  Files             ?      200           
  Lines             ?    15659           
  Branches          ?        0           
=========================================
  Hits              ?     8862           
  Misses            ?     5698           
  Partials          ?     1099

Flag	Coverage Δ
#critest	33.48% <ø> (?)
#integrationtest	37.69% <ø> (?)
#unittest	20.75% <ø> (?)