code: private Map<String, Integer> createMapOfColumnIndex(String[] columns)
      {
          int i = 0;
          Map<String, Integer> map = new HashMap<String, Integer>();
          for (String column : columns)
          {
              map.put(column, i++);
          }
          return map;
      }
docs: Creates the map of column index.
  
  @param columns
  the columns
  @return the map