code: @Override
      public List<DColumn> getColumns(String storeName, String rowKey, String startColumn, String endColumn, int count) {
          DBConn dbConn = getDBConnection();
          try {
              List<ColumnOrSuperColumn> columns = dbConn.getSlice(
                      CassandraDefs.columnParent(storeName),
                      CassandraDefs.slicePredicateStartEndCol(Utils.toBytes(startColumn), Utils.toBytes(endColumn), count),
                      Utils.toByteBuffer(rowKey));
              List<DColumn> result = new ArrayList<>(columns.size());
              for(ColumnOrSuperColumn column: columns) {
                  result.add(new DColumn(column.getColumn().getName(), column.getColumn().getValue()));
              }
              return result;
          } finally {
              returnDBConnection(dbConn);
          }
      }
docs: ----- Public DBService methods: Queries