title: grpc go : how to know in server side, when client closes the connection
body: <p>I am using grpc go</p>
  
  <p>i have an rpc which looks roughly like this</p>
  
  <pre><code>196 service MyService {
  197   // Operation 1
  198   rpc Operation1(OperationRequest) returns (OperationResponse) {
  199       option (google.api.http) = {
  200         post: "/apiver/myser/oper1"
  201         body: "*"
  202     };
  203   }
  </code></pre>
  
  <p>Client connects by using grpc.Dial() method</p>
  
  <p>When a client connects, the server does some book keeping. when the client disconnects, the bookkeeping needs to be removed.</p>
  
  <p>is there any callback that can be registered which can be used to know that client has closed the session.</p>