I tried to build new type, but SimpleFeatureType.getCoordinateReferenceSystem() returns null

    
   

         //create polygon
        GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory( );
        com.vividsolutions.jts.geom.Polygon polygonFromCoordinates = geometryFactory.createPolygon(coordinates);

        SimpleFeatureTypeBuilder b = new SimpleFeatureTypeBuilder();

        // set the name
        b.setName("Garden");

        // add some properties
        b.add("name", String.class);

        // add a geometry property
         CoordinateReferenceSystem coordinateReferenceSystem = DefaultGeographicCRS.WGS84;

        b.setCRS(coordinateReferenceSystem); // set crs first
        b.add("location", Polygon.class); // then add geometry
        b.crs(coordinateReferenceSystem);
        // build the type
        final SimpleFeatureType FLAG = b.buildFeatureType();
        System.out.println(FLAG.getCoordinateReferenceSystem());

        System.out.println(FLAG);