docs: private boolean contentExists( BinaryKey key,
                                     boolean alive ) throws BinaryStoreException {
          try {
              String query = "SELECT payload from modeshape.binary where cid='" + key.toString() + "'";
              query = alive ? query + " and usage=1;" : query + " and usage = 0;";
              ResultSet rs = session.execute(query);
              return rs.iterator().hasNext();
          } catch (RuntimeException e) {
              throw new BinaryStoreException(e);
          }
      }