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Posted to dev@flink.apache.org by Robert Metzger <rm...@apache.org> on 2019/08/07 12:27:05 UTC
Re: [DISCUSS] Adopting a Code Style and Quality Guide
Hi all,
I've now merged the guide to the Flink website:
https://flink.apache.org/contributing/code-style-and-quality-preamble.html
I'm looking forward to more pull requests enhancing the guide.
On Tue, Jul 23, 2019 at 7:22 PM Hugo Louro <hm...@gmail.com> wrote:
> Sounds good @stephan! Thanks.
>
> On Tue, Jul 23, 2019 at 10:15 AM Stephan Ewen <se...@apache.org> wrote:
>
> > @hugo For your suggestions, I would ask to start a separate discussion
> > thread.
> > I think this mail thread has converged towards merging the initial
> > suggestion as a starting point and refining it later based on new
> > discussions.
> >
> > Best,
> > Stephan
> >
> >
> > On Thu, Jun 27, 2019 at 10:48 PM Hugo Louro <hm...@gmail.com> wrote:
> >
> > > +1. Thanks for working on the guide. It's very thorough and a good
> > resource
> > > to learn good practices from.
> > >
> > > I would like use this thread as a placeholder for a couple of topics
> that
> > > may be deserving of further discussion on different threads:
> > > - What's the best way to keep track of checkstyle version updates.
> For
> > > instance, currently there is a PR
> > > <https://github.com/apache/flink/pull/8870> proposing checkstyle to be
> > > updated because version 8.12 is no longer supported
> > > - When classes import shaded dependencies, it is not trivial for
> > IntelliJ
> > > to download and associate sources and javadocs, which makes debugging
> and
> > > navigate the code base harder. I tried installing the version of the
> > > library using maven from the CLI, and associate the sources "manually"
> on
> > > IntelliJ, but it seems it does not work (perhaps IntelliJ issue). Does
> > > anyone know of a good solution? If so, we should added here
> > > <
> > >
> >
> https://ci.apache.org/projects/flink/flink-docs-release-1.8/flinkDev/ide_setup.html#intellij-idea
> > > >.
> > > I can volunteer for that if you tell me how to do it :)
> > > - did the community evaluate naming test methods according to these
> > > conventions <https://stackoverflow.com/a/1594049> ?
> > >
> > > Thanks
> > >
> > > On Mon, Jun 24, 2019 at 11:38 AM Stephan Ewen <se...@apache.org>
> wrote:
> > >
> > > > I think it makes sense to also start individual [DISCUSS] threads
> about
> > > > extensions and follow-ups.
> > > > Various suggestions came up, partly as comments in the doc, some as
> > > > questions in other threads.
> > > >
> > > > Examples:
> > > > - use of null in return types versus Optional versus
> > @Nullable/@Nonnull
> > > > - initialization of collection sizes
> > > > - logging
> > > >
> > > > I think these would be best discussed in separate threads each.
> > > > So, for contributors to whom these issues are dear, feel free to
> spawn
> > > > these additional threads.
> > > > (Bear in mind it is close to 1.9 feature freeze time, so please leave
> > > this
> > > > discussions a bit of time so that all community members have a chance
> > to
> > > > participate)
> > > >
> > > >
> > > >
> > > > On Mon, Jun 24, 2019 at 7:51 PM Stephan Ewen <se...@apache.org>
> wrote:
> > > >
> > > > > Thanks for the pointer David.
> > > > >
> > > > > I was not aware of this tool and I have no experience with its
> > > practical
> > > > > impact. For example I would be curious what the effect of this is
> for
> > > > > existing PRs, merge conflicts, etc.
> > > > >
> > > > > If you want, feel free to start another discuss thread on the
> > > > introduction
> > > > > of such a tool.
> > > > >
> > > > > On Sun, Jun 23, 2019 at 6:32 PM David Morávek <dm...@apache.org>
> > wrote:
> > > > >
> > > > >> I love this kind of unification being pushed forward, the benefit
> it
> > > has
> > > > >> on
> > > > >> code reviews is enormous. Just my two cents, did you guys think
> > about
> > > > >> adopting an automatic code formatter for java, the same way as
> > Apache
> > > > Beam
> > > > >> did?
> > > > >>
> > > > >> It is super easy to use for contributors as they don't need to
> keep
> > > any
> > > > >> particular coding style in mind and they can only focus on
> > > functionality
> > > > >> they want to fix, and it's also great for reviewers, because they
> > only
> > > > see
> > > > >> the important changes. This also eliminates need for any special
> > > editor
> > > > /
> > > > >> checkstyle configs as the code formatting is part of the build
> > itself.
> > > > >>
> > > > >> The one Beam uses is https://github.com/diffplug/spotless with
> > > > >> GoogleJavaFormat, it may be worth to look into.
> > > > >>
> > > > >> Best,
> > > > >> David
> > > > >>
> > > > >> On Fri, Jun 21, 2019 at 4:40 PM Stephan Ewen <se...@apache.org>
> > > wrote:
> > > > >>
> > > > >> > Thanks, everyone, for the positive feedback :-)
> > > > >> >
> > > > >> > @Robert - It probably makes sense to break this down into
> various
> > > > pages,
> > > > >> > like PR, general code style guide, Java, component specific
> > guides,
> > > > >> > formats, etc.
> > > > >> >
> > > > >> > Best,
> > > > >> > Stephan
> > > > >> >
> > > > >> >
> > > > >> > On Fri, Jun 21, 2019 at 4:29 PM Robert Metzger <
> > rmetzger@apache.org
> > > >
> > > > >> > wrote:
> > > > >> >
> > > > >> > > It seems that the discussion around this topic has settled.
> > > > >> > >
> > > > >> > > I'm going to turn the Google Doc into a markdown file (maybe
> > also
> > > > >> > multiple,
> > > > >> > > I'll try out different things) and then open a pull request
> for
> > > the
> > > > >> Flink
> > > > >> > > website.
> > > > >> > > I'll post a link to the PR here once I'm done.
> > > > >> > >
> > > > >> > > On Fri, Jun 14, 2019 at 9:36 AM zhijiang <
> > > > wangzhijiang999@aliyun.com
> > > > >> > > .invalid>
> > > > >> > > wrote:
> > > > >> > >
> > > > >> > > > Thanks for providing this useful guide for benefiting both
> > > > >> contributors
> > > > >> > > > and committers in consistency.
> > > > >> > > >
> > > > >> > > > I just reviewed and learned the whole doc which covers a lot
> > of
> > > > >> > > > information. Wish it further categoried and put onto
> somewhere
> > > for
> > > > >> > easily
> > > > >> > > > traced future.
> > > > >> > > >
> > > > >> > > > Best,
> > > > >> > > > Zhijiang
> > > > >> > > >
> > > ------------------------------------------------------------------
> > > > >> > > > From:Robert Metzger <rm...@apache.org>
> > > > >> > > > Send Time:2019年6月14日(星期五) 14:24
> > > > >> > > > To:dev <de...@flink.apache.org>
> > > > >> > > > Subject:Re: [DISCUSS] Adopting a Code Style and Quality
> Guide
> > > > >> > > >
> > > > >> > > > Thanks a lot for putting this together!
> > > > >> > > >
> > > > >> > > > I'm in the process of reworking the "How to contribute"
> pages
> > > [1]
> > > > >> and
> > > > >> > I'm
> > > > >> > > > happy to add the guide to the Flink website, once the
> > discussion
> > > > >> here
> > > > >> > is
> > > > >> > > > over.
> > > > >> > > >
> > > > >> > > > [1] https://github.com/apache/flink-web/pull/217
> > > > >> > > >
> > > > >> > > > On Fri, Jun 14, 2019 at 3:21 AM Kurt Young <
> ykt836@gmail.com>
> > > > >> wrote:
> > > > >> > > >
> > > > >> > > > > Big +1 and thanks for preparing this.
> > > > >> > > > >
> > > > >> > > > > I think wha't more important is making sure most all the
> > > > >> contributors
> > > > >> > > can
> > > > >> > > > > follow
> > > > >> > > > > the same guide, a clear document is definitely a great
> > start.
> > > > >> > > Committers
> > > > >> > > > > can
> > > > >> > > > > first try to follow the guide by self, and spread the
> > standard
> > > > >> during
> > > > >> > > > code
> > > > >> > > > > reviewing.
> > > > >> > > > >
> > > > >> > > > > Best,
> > > > >> > > > > Kurt
> > > > >> > > > >
> > > > >> > > > >
> > > > >> > > > > On Thu, Jun 13, 2019 at 8:28 PM Congxian Qiu <
> > > > >> qcx978132955@gmail.com
> > > > >> > >
> > > > >> > > > > wrote:
> > > > >> > > > >
> > > > >> > > > > > +1 for this, I think all contributors can benefit from
> > this.
> > > > >> > > > > >
> > > > >> > > > > > Best,
> > > > >> > > > > > Congxian
> > > > >> > > > > >
> > > > >> > > > > >
> > > > >> > > > > > Aljoscha Krettek <al...@apache.org> 于2019年6月13日周四
> > > > 下午8:14写道：
> > > > >> > > > > >
> > > > >> > > > > > > +1 I think this is a very good effort and should put
> to
> > > rest
> > > > >> some
> > > > >> > > > > > > back-and-forth discussions on PRs and some differences
> > in
> > > > >> “style”
> > > > >> > > > > between
> > > > >> > > > > > > committers. ;-)
> > > > >> > > > > > >
> > > > >> > > > > > > > On 13. Jun 2019, at 10:21, JingsongLee <
> > > > >> > lzljs3620320@aliyun.com
> > > > >> > > > > > .INVALID>
> > > > >> > > > > > > wrote:
> > > > >> > > > > > > >
> > > > >> > > > > > > > big +1, the content is very useful and enlightening.
> > > > >> > > > > > > > But it's really too long to look at.
> > > > >> > > > > > > > +1 for splitting it and expose it to contributors.
> > > > >> > > > > > > >
> > > > >> > > > > > > > Even I think it's possible to put its link on the
> > > default
> > > > >> > > > description
> > > > >> > > > > > of
> > > > >> > > > > > > > pull request, so that the user has to see it when
> > > submits
> > > > >> the
> > > > >> > > code.
> > > > >> > > > > > > >
> > > > >> > > > > > > > Best, JingsongLee
> > > > >> > > > > > > >
> > > > >> > > > > > > >
> > > > >> > > > > > > >
> > > > >> > >
> > ------------------------------------------------------------------
> > > > >> > > > > > > > From:Piotr Nowojski <pi...@ververica.com>
> > > > >> > > > > > > > Send Time:2019年6月13日(星期四) 16:03
> > > > >> > > > > > > > To:dev <de...@flink.apache.org>
> > > > >> > > > > > > > Subject:Re: [DISCUSS] Adopting a Code Style and
> > Quality
> > > > >> Guide
> > > > >> > > > > > > >
> > > > >> > > > > > > > +1 for it and general content and thank everybody
> that
> > > was
> > > > >> > > involved
> > > > >> > > > > in
> > > > >> > > > > > > creating & writing this down.
> > > > >> > > > > > > >
> > > > >> > > > > > > > +1 for splitting it up into some easily navigable
> > > topics.
> > > > >> > > > > > > >
> > > > >> > > > > > > > Piotrek
> > > > >> > > > > > > >
> > > > >> > > > > > > >> On 13 Jun 2019, at 09:54, Stephan Ewen <
> > > sewen@apache.org
> > > > >
> > > > >> > > wrote:
> > > > >> > > > > > > >>
> > > > >> > > > > > > >> This should definitely be split up into topics,
> > agreed.
> > > > >> > > > > > > >> And it should be linked form the "how to
> contribute"
> > > page
> > > > >> or
> > > > >> > the
> > > > >> > > > PR
> > > > >> > > > > > > >> template to make contributors aware.
> > > > >> > > > > > > >>
> > > > >> > > > > > > >> On Thu, Jun 13, 2019 at 9:51 AM Zili Chen <
> > > > >> > wander4096@gmail.com
> > > > >> > > >
> > > > >> > > > > > wrote:
> > > > >> > > > > > > >>
> > > > >> > > > > > > >>> Thanks for creating this guide Stephan. It is also
> > > > >> > > > > > > >>> a good start point to internals doc.
> > > > >> > > > > > > >>>
> > > > >> > > > > > > >>> One suggestion is we could finally separate the
> > guide
> > > > >> > > > > > > >>> into separated files each of which focus on a
> > specific
> > > > >> > > > > > > >>> topic. Besides, add the guide to our repository
> > should
> > > > >> > > > > > > >>> make contributors more aware of it.
> > > > >> > > > > > > >>>
> > > > >> > > > > > > >>> Best,
> > > > >> > > > > > > >>> tison.
> > > > >> > > > > > > >>>
> > > > >> > > > > > > >>>
> > > > >> > > > > > > >>> Jeff Zhang <zj...@gmail.com> 于2019年6月13日周四
> > 下午3:35写道：
> > > > >> > > > > > > >>>
> > > > >> > > > > > > >>>> Thanks for the proposal, Stephan. Big +1 on this.
> > > > >> > > > > > > >>>>
> > > > >> > > > > > > >>>> This is definitely helpful and indispensable for
> > > > flink's
> > > > >> > code
> > > > >> > > > > > quality
> > > > >> > > > > > > and
> > > > >> > > > > > > >>>> healthy community growth.
> > > > >> > > > > > > >>>> It would also benefit downstream project to
> > integrate
> > > > >> flink
> > > > >> > > > > easier.
> > > > >> > > > > > > >>>>
> > > > >> > > > > > > >>>>
> > > > >> > > > > > > >>>> Till Rohrmann <tr...@apache.org>
> 于2019年6月13日周四
> > > > >> > 下午3:29写道：
> > > > >> > > > > > > >>>>
> > > > >> > > > > > > >>>>> Thanks for creating this code style and quality
> > > guide
> > > > >> > > Stephan.
> > > > >> > > > I
> > > > >> > > > > > > think
> > > > >> > > > > > > >>>>> Flink can benefit from such a guide. Thus +1 for
> > > > >> > introducing
> > > > >> > > > and
> > > > >> > > > > > > >>> adhering
> > > > >> > > > > > > >>>>> to it.
> > > > >> > > > > > > >>>>>
> > > > >> > > > > > > >>>>> Cheers,
> > > > >> > > > > > > >>>>> Till
> > > > >> > > > > > > >>>>>
> > > > >> > > > > > > >>>>> On Thu, Jun 13, 2019 at 5:26 AM Bowen Li <
> > > > >> > > bowenli86@gmail.com>
> > > > >> > > > > > > wrote:
> > > > >> > > > > > > >>>>>
> > > > >> > > > > > > >>>>>> Hi Stephan,
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>> Definitely a good guide in principle IMO! I
> > > > personally
> > > > >> > > already
> > > > >> > > > > > find
> > > > >> > > > > > > >>> it
> > > > >> > > > > > > >>>>>> useful in practice to learn from it myself, and
> > > also
> > > > >> > promote
> > > > >> > > > and
> > > > >> > > > > > > >>>>> cultivate
> > > > >> > > > > > > >>>>>> a better coding habit around by referencing it.
> > So
> > > > big
> > > > >> +1
> > > > >> > to
> > > > >> > > > > adopt
> > > > >> > > > > > > >>> it.
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>> Also want to highlight that we need to make
> real
> > > use
> > > > of
> > > > >> > it,
> > > > >> > > > and
> > > > >> > > > > > keep
> > > > >> > > > > > > >>>>>> ensuring people are aware of its existence.
> > Adding
> > > it
> > > > >> to
> > > > >> > > Flink
> > > > >> > > > > > > >>> website
> > > > >> > > > > > > >>>>>> would be nice. We can also adding noticeable
> link
> > > for
> > > > >> it
> > > > >> > to
> > > > >> > > > the
> > > > >> > > > > > > >>>> template
> > > > >> > > > > > > >>>>> of
> > > > >> > > > > > > >>>>>> github PR (where this guide really matters) to
> > get
> > > > >> > attention
> > > > >> > > > and
> > > > >> > > > > > > >>>>> exposure.
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>> BTW, what's the plan on how people can raise
> new
> > > > >> > > > > > > coding-style/quality
> > > > >> > > > > > > >>>>>> related questions, how to expand and adjust the
> > > > content
> > > > >> > over
> > > > >> > > > > time,
> > > > >> > > > > > > >>> how
> > > > >> > > > > > > >>>> to
> > > > >> > > > > > > >>>>>> inform the community of such updates and
> changes?
> > > > >> Maybe we
> > > > >> > > can
> > > > >> > > > > use
> > > > >> > > > > > > >>> some
> > > > >> > > > > > > >>>>>> tags like "[CODING STYLE]" in dev mailing list
> > for
> > > > >> these
> > > > >> > > type
> > > > >> > > > of
> > > > >> > > > > > > >>>>>> communications? This can be a separate
> discussion
> > > > >> though
> > > > >> > if
> > > > >> > > we
> > > > >> > > > > > wish.
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>> All in all, big +1 for adopting it.
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>> Bowen
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>> On Wed, Jun 12, 2019 at 12:32 PM Stephan Ewen <
> > > > >> > > > sewen@apache.org
> > > > >> > > > > >
> > > > >> > > > > > > >>>> wrote:
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>>> Hi all!
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> I want to propose that we try and adopt a code
> > > style
> > > > >> and
> > > > >> > > > > quality
> > > > >> > > > > > > >>>> guide.
> > > > >> > > > > > > >>>>>> Its
> > > > >> > > > > > > >>>>>>> a big endeavor, but I think it's worth trying
> > :-)
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> The Apache Flink community and contributor
> base
> > is
> > > > >> > growing
> > > > >> > > > > quite
> > > > >> > > > > > a
> > > > >> > > > > > > >>>> bit,
> > > > >> > > > > > > >>>>>> new
> > > > >> > > > > > > >>>>>>> committers and contributors are coming on
> board
> > > > >> > frequently.
> > > > >> > > > > > > >>> Everyone
> > > > >> > > > > > > >>>>>> comes
> > > > >> > > > > > > >>>>>>> from a different background and brings a
> > different
> > > > >> level
> > > > >> > of
> > > > >> > > > > > > >>>> experience.
> > > > >> > > > > > > >>>>>>> Different contributors apply different styles,
> > and
> > > > >> > > > > contributions
> > > > >> > > > > > > >>> are
> > > > >> > > > > > > >>>>>>> naturally of varying code quality.
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> We are struggling with finding a good balance
> > > > between:
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> (1) On the one hand maintaining a certain code
> > > > >> standard
> > > > >> > > for a
> > > > >> > > > > big
> > > > >> > > > > > > >>>> and
> > > > >> > > > > > > >>>>>>> complex system like Flink, to reduce bugs and
> > make
> > > > >> future
> > > > >> > > > > > > >>>> contributions
> > > > >> > > > > > > >>>>>>> feasible (and not impossible due to code
> > > > complexity).
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> (2) On the other hand, make contributions
> > possible
> > > > for
> > > > >> > > > > > > >>>> contributors.
> > > > >> > > > > > > >>>>>> This
> > > > >> > > > > > > >>>>>>> means not guarding everything to the point
> that
> > no
> > > > >> > > > > contributions
> > > > >> > > > > > > >>> can
> > > > >> > > > > > > >>>>> get
> > > > >> > > > > > > >>>>>> in
> > > > >> > > > > > > >>>>>>> any more.
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> My suggestion to help with this is to define a
> > > > >> standard
> > > > >> > and
> > > > >> > > > > > > >>> document
> > > > >> > > > > > > >>>> it
> > > > >> > > > > > > >>>>>>> explicitly. It will help to get everyone on
> the
> > > same
> > > > >> page
> > > > >> > > > what
> > > > >> > > > > > the
> > > > >> > > > > > > >>>>>>> expectation is, and it helps contributors know
> > > what
> > > > to
> > > > >> > pay
> > > > >> > > > > > > >>> attention
> > > > >> > > > > > > >>>>> to.
> > > > >> > > > > > > >>>>>>> Such a guide should also help make review more
> > > > >> efficient,
> > > > >> > > > > because
> > > > >> > > > > > > >>>>>>> contributors can know up front what reviewers
> > will
> > > > >> look
> > > > >> > at.
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> Over the past weeks, I took a look at the
> > current
> > > > >> Flink
> > > > >> > > code
> > > > >> > > > > base
> > > > >> > > > > > > >>> and
> > > > >> > > > > > > >>>>>>> talked to some committers and contributors and
> > > tried
> > > > >> to
> > > > >> > > come
> > > > >> > > > up
> > > > >> > > > > > > >>> with
> > > > >> > > > > > > >>>> a
> > > > >> > > > > > > >>>>>>> proposal that reflects the approaches and
> > > standards
> > > > >> that
> > > > >> > > many
> > > > >> > > > > > > >>>>> committers
> > > > >> > > > > > > >>>>>>> have adopted lately.
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>
> > > > >> > > > > > > >>>>
> > > > >> > > > > > > >>>
> > > > >> > > > > > >
> > > > >> > > > > >
> > > > >> > > > >
> > > > >> > > >
> > > > >> > >
> > > > >> >
> > > > >>
> > > >
> > >
> >
> https://docs.google.com/document/d/1owKfK1DwXA-w6qnx3R7t2D_o0BsFkkukGlRhvl3XXjQ
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> This guide is not fix and final, we should
> > discuss
> > > > it
> > > > >> and
> > > > >> > > > > expand
> > > > >> > > > > > > >>> and
> > > > >> > > > > > > >>>>>> adjust
> > > > >> > > > > > > >>>>>>> it over time. The guide tries to strike a
> > balance
> > > > >> between
> > > > >> > > too
> > > > >> > > > > > much
> > > > >> > > > > > > >>>>>> contents
> > > > >> > > > > > > >>>>>>> (don't force someone to read a book before
> > > > >> contributing)
> > > > >> > > and
> > > > >> > > > > > being
> > > > >> > > > > > > >>>>>>> comprehensive enough. The guide looks long,
> but
> > > much
> > > > >> of
> > > > >> > it
> > > > >> > > > are
> > > > >> > > > > > > >>>>> component
> > > > >> > > > > > > >>>>>> or
> > > > >> > > > > > > >>>>>>> aspect specific parts, like how to deal with
> new
> > > > >> > > > dependencies,
> > > > >> > > > > > > >>>>>>> configuration changes, etc.
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> I an curious to hear whether you think such a
> > > guide
> > > > >> is in
> > > > >> > > > > > > >>> principle a
> > > > >> > > > > > > >>>>>> good
> > > > >> > > > > > > >>>>>>> idea.
> > > > >> > > > > > > >>>>>>> If yes, is the one here a good starting point?
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>> Best,
> > > > >> > > > > > > >>>>>>> Stephan
> > > > >> > > > > > > >>>>>>>
> > > > >> > > > > > > >>>>>>
> > > > >> > > > > > > >>>>>
> > > > >> > > > > > > >>>>
> > > > >> > > > > > > >>>>
> > > > >> > > > > > > >>>> --
> > > > >> > > > > > > >>>> Best Regards
> > > > >> > > > > > > >>>>
> > > > >> > > > > > > >>>> Jeff Zhang
> > > > >> > > > > > > >>>>
> > > > >> > > > > > >
> > > > >> > > > > > >
> > > > >> > > > > >
> > > > >> > > > >
> > > > >> > > >
> > > > >> > > >
> > > > >> > >
> > > > >> >
> > > > >>
> > > > >
> > > >
> > >
> >
>