code: def compileGSUB(featureFile, glyphOrder):
      
      font = ttLib.TTFont()
      font.setGlyphOrder(glyphOrder)
      addOpenTypeFeatures(font, featureFile, tables={"GSUB"})
      return font.get("GSUB")
docs: Compile and return a GSUB table from `featureFile` (feaLib
      FeatureFile), using the given `glyphOrder` (list of glyph names).