code: private Statement blockDeleteStatement(BlockedDeltaTableDDL tableDDL, ByteBuffer rowKey, UUID changeId, int block, ConsistencyLevel consistencyLevel) {
          return QueryBuilder.delete()
                  .from(tableDDL.getTableMetadata())
                  .where(eq(tableDDL.getRowKeyColumnName(), rowKey))
                  .and(eq(tableDDL.getChangeIdColumnName(), changeId))
                  .and(eq(tableDDL.getBlockColumnName(), block))
                  .setConsistencyLevel(consistencyLevel);
      }
docs: This method returns a delete statement for a single block, rather than the delta as whole. In order to delete an
  entire delta using this method, it should be called once for each block. In cases in which there are relatively
  few blocks in a delta, this method can be more efficient than {@link #deleteStatement(TableDDL, ByteBuffer, UUID, ConsistencyLevel)},
  as the cell tombstones created by this method are more efficient than range tombstones