which automatically fetches submodel. Needs docstrings... Part of https://github.com/googlei18n/fontmake/issues/88 Part of https://github.com/fonttools/fonttools/issues/1355
which automatically fetches submodel. Needs docstrings... Part of https://github.com/googlei18n/fontmake/issues/88 Part of https://github.com/fonttools/fonttools/issues/1355