code: public Iterable<DRow> getRows(String storeName, Collection<String> rowKeys) {
          List<DRow> rows = new ArrayList<>(rowKeys.size());
          for(String rowKey: rowKeys) {
              rows.add(new DRow(m_tenant, storeName, rowKey));
          }
          return rows;
      }
docs: Get iterator for rows with a specific set of keys. Results are returned as an
  Iterator of {@link DRow} objects. If any given row is not found, no entry
  with its key will be returned.
  
  @param storeName Name of store to query.
  @param rowKeys   Collection of row keys to read.
  @return          Iterator of {@link DRow} objects. May be empty but not null.