transform_expressions_test - add global attribute tests ( e.g @value ) ref #3569
transform_expressions_test - add global attribute tests ( e.g @value ) ref #3569

tomhughes/mapnik,mapnik/mapnik,lightmare/mapnik,mapnik/mapnik,naturalatlas/mapnik,lightmare/mapnik,mapnik/mapnik,naturalatlas/mapnik,mapnik/mapnik,lightmare/mapnik,tomhughes/mapnik,tomhughes/mapnik,naturalatlas/mapnik,lightmare/mapnik,naturalatlas/mapnik,tomhughes/mapnik