How to use the ufo2ft.featureWriters.ast.makeGlyphClassDefinitions function in ufo2ft

def _makeMarkFilteringSetClass(self, lookupName, attachments, markClass, include):
        markGlyphs = (glyphName for glyphName in markClass.glyphs if include(glyphName))
        baseGlyphs = (
            pos.name for pos in attachments if pos.name not in markClass.glyphs
        )
        members = itertools.chain(markGlyphs, baseGlyphs)
        className = "MFS_%s" % lookupName
        return ast.makeGlyphClassDefinitions(
            {className: members}, feaFile=self.context.feaFile
        )[className]

def getKerningClasses(cls, font, feaFile=None, glyphSet=None):
        side1Groups, side2Groups = cls.getKerningGroups(font, glyphSet)
        side1Classes = ast.makeGlyphClassDefinitions(
            side1Groups, feaFile, stripPrefix="public."
        )
        side2Classes = ast.makeGlyphClassDefinitions(
            side2Groups, feaFile, stripPrefix="public."
        )
        return side1Classes, side2Classes

def getKerningClasses(cls, font, feaFile=None, glyphSet=None):
        side1Groups, side2Groups = cls.getKerningGroups(font, glyphSet)
        side1Classes = ast.makeGlyphClassDefinitions(
            side1Groups, feaFile, stripPrefix="public."
        )
        side2Classes = ast.makeGlyphClassDefinitions(
            side2Groups, feaFile, stripPrefix="public."
        )
        return side1Classes, side2Classes