title: Hyperledger accessing transaction ID in invoke function
body: <p>if I call Invoke of chain code, I get transaction ID in REST response. e.g.</p>
  
  <pre><code>{
    "jsonrpc": "2.0",
    "result": {
      "status": "OK",
      "message": "e00848bc-71c3-422f-b637-cbfc9d2e2042"
    },
    "id": 4
  }
  </code></pre>
  
  <p>How can I access this transaction ID (e00848bc-71c3-422f-b637-cbfc9d2e2042 in above example) programatically in my invoke function of chaincode?</p>