code: public String getColumnText(Object element, int columnIndex) {
      if (element instanceof HadoopServer) {
        HadoopServer server = (HadoopServer) element;
  
        switch (columnIndex) {
          case 0:
            return server.getLocationName();
          case 1:
            return server.getMasterHostName().toString();
          case 2:
            return server.getState();
          case 3:
            return "";
        }
      } else if (element instanceof HadoopJob) {
        HadoopJob job = (HadoopJob) element;
  
        switch (columnIndex) {
          case 0:
            return job.getJobID().toString();
          case 1:
            return "";
          case 2:
            return job.getState().toString();
          case 3:
            return job.getStatus();
        }
      } else if (element instanceof JarModule) {
        JarModule jar = (JarModule) element;
  
        switch (columnIndex) {
          case 0:
            return jar.toString();
          case 1:
            return "Publishing jar to server..";
          case 2:
            return "";
        }
      }
  
      return null;
    }
docs: /* @inheritDoc