code: @Override
      public String[] getColumns() {
          if (metaData != null && columns == null) {
              final List<ColumnMetaData> cmds = metaData.getColumnsNames();
  
              columns = new String[cmds.size()];
              for (int i = 0; i < cmds.size(); i++) {
                  columns[i] = cmds.get(i).getColName();
              }
          }
  
          return columns;
      }
docs: /*
  (non-Javadoc)
  
  @see net.sf.flatpack.DataSet#getColumns()