Support was added in db49f20d6b2629e1ba25c4afd3fb60817387f3d6, but there was only a parser test and no builder test, fix the build and add a builder test based on the existing parser one. Fixes https://github.com/fonttools/fonttools/issues/1901
Support was added in db49f20d6b2629e1ba25c4afd3fb60817387f3d6, but there was only a parser test and no builder test, fix the build and add a builder test based on the existing parser one. Fixes https://github.com/fonttools/fonttools/issues/1901