private void stopProcedureExecutor() {
    if (this.procedureEnv != null) {
      this.procedureEnv.getRemoteDispatcher().stop();
    }

    if (this.procedureExecutor != null) {
      this.procedureExecutor.stop();
    }

    if (this.procedureStore != null) {
      this.procedureStore.stop(isAborted());
    }
  }
Call this restart method only after running MockMasterServices#start() The RSs can be
differentiated by the port number, see ServerName in MockMasterServices#start() method above.
Restart of region server will have new startcode in server name
@param serverName Server name to be restarted
hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/MockMasterServices.java