code: @Override
      public int removeProperties(String pattern, Character escape) throws Exception {
          StringBuilder delete = new StringBuilder(58)
                          .append("DELETE FROM Property WHERE ID LIKE :pattern");
          if (escape != null)
              delete.append(" ESCAPE :escape");
  
          final boolean trace = TraceComponent.isAnyTracingEnabled();
          if (trace && tc.isEntryEnabled())
              Tr.entry(this, tc, "removeProperties", pattern, escape, delete);
  
          EntityManager em = getPersistenceServiceUnit().createEntityManager();
          try {
              Query query = em.createQuery(delete.toString());
              query.setParameter("pattern", pattern);
              if (escape != null)
                  query.setParameter("escape", escape);
              int count = query.executeUpdate();
  
              if (trace && tc.isEntryEnabled())
                  Tr.exit(this, tc, "removeProperties", count);
              return count;
          } finally {
              em.close();
          }
      }
docs: {@inheritDoc}