private QueryField toDataSourceField(final FieldType elasticIndexFieldType,
                                         final String fieldName,
                                         final Boolean isIndexed)
            throws IllegalArgumentException {
        final ConditionSet conditionSet = ConditionSet.getElastic(elasticIndexFieldType);
        return QueryField
                .builder()
                .fldName(fieldName)
                .fldType(elasticIndexFieldType)
                .conditionSet(conditionSet)
                .queryable(isIndexed)
                .build();
    }
Returns an `AbstractField` instance, based on the field's data type
stroom-search/stroom-search-elastic/src/main/java/stroom/search/elastic/search/ElasticSearchProvider.java