code: public Iterable<DColumn> getColumnSlice(String storeName, String rowKey, String startCol, String endCol) {
          DRow row = new DRow(m_tenant, storeName, rowKey);
          return row.getColumns(startCol, endCol, 1024);
      }
docs: Get columns for the row with the given key in the given store. Columns range
  is defined by an interval [startCol, endCol]. Columns are returned
  as an Iterator of {@link DColumn}s. Empty iterator is returned if no row
  is found with the given key or no columns in the given interval found.
  
  @param storeName Name of store to query.
  @param rowKey    Key of row to fetch.
  @param startCol	First name in the column names interval.
  @param endCol	Last name in the column names interval.
  @return          Iterator of {@link DColumn}s. If there is no such row, the
  iterator's hasNext() will be false.