docs: public void combine(Vector new_filters, int op) throws DBException
      {
          // If this is not a logical operator, throw an exception
          if ((op & LOGICAL_OPER_MASK) == 0)
          {
              throw new DBException();
              // Create a new vector consisting of just the filters
              // from the SearchFilter classes in new_filters
          }
          Vector filters = new Vector();
          // Now add in all the nodes of the new filters
          for (Enumeration e = new_filters.elements(); e.hasMoreElements();)
          {
              // Get the search filter from the vector
              SearchFilter f = (SearchFilter) e.nextElement();
              filters.addElement(f.getFilter());
          }
          // Create a node for this list and return it
          m_filter = new SearchBaseNode(op, m_filter, filters);
      }