tikv: update the usage example for Txn KV API#487

Merged

lilin90 merged 3 commits intopingcap:masterfrom lilin90:tikv-txn-api

Jun 14, 2018

Commits on Jun 7, 2018

tikv: update the usage example for Txn KV API
lilin90
committed

Commits on Jun 8, 2018

tikv: update the code fencing
lilin90
committed

Commits on Jun 12, 2018

tikv: address comments
lilin90
committed