code: public User addUser(Set<User> users) throws Exception
      {
  
          if (m_iCurrentRow == m_iNbRows)
              return null;
  
          Row row = m_sheet.getRow(m_iCurrentRow);
          if (row == null)
          {
              return null;
          }
          else
          {
              // extract fields from excel sheet
              String userName = extractCellData(row, 0);
              String tweetBody = extractCellData(row, 1);
              String videoId = extractCellData(row, 2);
              String videoName = extractCellData(row, 3);
  
              User user = null;
              boolean present = false;
              
              //iterate over fields.
              for (Iterator iterator = users.iterator(); iterator.hasNext();)
              {
                  user = (User) iterator.next();
                  if (user.getFirstName().equals(userName))
                  {
                      present = true;
                      break;
                  }
              }
  
              if (!present)
              {
                  user = addUser(userName);
              }
  
              Tweets tweet = addTweets(user, tweetBody, new Date(), m_iCurrentRow + "");
              assignVideosToTweet(tweet, videoId, videoName);
  
              m_iCurrentRow++;
  
              return user;
          }
  
      }
docs: /*
  Returns the contents of an Excel row in the form of a String array.
  
  @see com.ibm.ccd.common.parsing.Parser#splitLine()