private static Condition CreateConditionUsingFragment(
            MappingFragment mappingFragment, Property tableColumn, bool? isNull, string conditionValue)
        {
            var cond = mappingFragment.FindConditionForColumn(tableColumn);
            if (cond == null)
            {
                cond = new Condition(mappingFragment, null);
                cond.ColumnName.SetRefName(tableColumn);
                mappingFragment.AddCondition(cond);

                XmlModelHelper.NormalizeAndResolve(cond);
            }

            if (cond == null)
            {
                throw new ItemCreationFailureException();
            }

            ModelHelper.SetConditionPredicate(cond, isNull, conditionValue);

            return cond;
        }