code: public Object getUniqueValue(FieldDescriptor field) throws SequenceManagerException
      {
          Object result = field.getJdbcType().sequenceKeyConversion(new Long(getUniqueLong(field)));
          // perform a sql to java conversion here, so that clients do
          // not see any db specific values
          result = field.getFieldConversion().sqlToJava(result);
          return result;
      }
docs: Returns a unique object for the given field attribute.
  The returned value takes in account the jdbc-type
  and the FieldConversion.sql2java() conversion defined for <code>field</code>.
  The returned object is unique accross all tables in the extent
  of class the field belongs to.