code: public Reply quote(String command) throws IOException, ServerException {
          Command cmd = new Command(command);
          return doCommand(cmd);
      }
docs: Executes arbitrary operation on the server.
  
  <br><b>Note</b>: <i>This is potentially dangerous operation.
  Depending on the command executed it might put the server in a
  different state from the state the client is expecting.</i>
  
  @param command command to execute
  @exception IOException in case of I/O error.
  @exception ServerException if operation failed.
  @return the Reply to the operation.