private boolean isConnected() {
    return connected;
  }
Below function executes command with retries with given user. Uses LocalShell to execute a
command.
@param user user name, default none
@param cmd  Command to execute
@return A pair of Exit Code and Shell output
@throws IOException Exception while executing shell command
hbase-it/src/main/java/org/apache/hadoop/hbase/chaos/ChaosAgent.java