add an example test for GetPrefixRangeEnd

[harryge00]

Contributing guidelines

Please read our contribution workflow before submitting a pull request.

GetPrefixRangeEnd has not been tested in clientv3. Add it in ExampleKV_getSortedPrefix()

[heyitsanthony]

It's already covered/tested: https://codecov.io/gh/coreos/etcd/src/9e574afb84ca88b68ca2c56542cf872ce34a1b2f/clientv3/op.go#L305

If there's going to be an example it shouldn't hang off the sort example since it doesn't really demonstrate the purpose of the function.

[harryge00]

@heyitsanthony I have just moved the block to another function. ExampleKV_getAscendingSortedPrefix

In ExampleKV_getSortedPrefix, clientv3.WithPrefix() is tested. So I wrote another function to test clientv3.WithRange(clientv3.GetPrefixRangeEnd("key"))... I think they are different.

[harryge00]

I have just began reading the code of etcd and want to contribute. I was wondering if there would be any minor feature I can do...

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@86eced6). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #8175   +/-   ##
=========================================
  Coverage          ?   76.46%           
=========================================
  Files             ?      344           
  Lines             ?    26886           
  Branches          ?        0           
=========================================
  Hits              ?    20558           
  Misses            ?     4854           
  Partials          ?     1474

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 86eced6...54807bf. Read the comment docs.

[xiang90]

@harryge00 probably take a look at #8060?

[xiang90]

closing this pr since the same thing already exists.