How to use the breathe.parser.doxygen.index function in breathe

def create_factory(self, project_info, document):

        renderers = {
            index.DoxygenTypeSub : indexrenderer.DoxygenTypeSubRenderer,
            index.CompoundTypeSub : CreateCompoundTypeSubRenderer(self.parser_factory),
            compound.DoxygenTypeSub : compoundrenderer.DoxygenTypeSubRenderer,
            compound.compounddefTypeSub : compoundrenderer.CompoundDefTypeSubRenderer,
            compound.sectiondefTypeSub : compoundrenderer.SectionDefTypeSubRenderer,
            compound.memberdefTypeSub : compoundrenderer.MemberDefTypeSubRenderer,
            compound.linkedTextTypeSub : compoundrenderer.LinkedTextTypeSubRenderer,
            compound.descriptionTypeSub : compoundrenderer.DescriptionTypeSubRenderer,
            compound.paramTypeSub : compoundrenderer.ParamTypeSubRenderer,
            compound.docRefTextTypeSub : compoundrenderer.DocRefTextTypeSubRenderer,
            compound.docParaTypeSub : compoundrenderer.DocParaTypeSubRenderer,
            compound.docParamListTypeSub : compoundrenderer.DocParamListTypeSubRenderer,
            compound.docParamListItemSub : compoundrenderer.DocParamListItemSubRenderer,
            compound.docParamNameListSub : compoundrenderer.DocParamNameListSubRenderer,
            compound.docParamNameSub : compoundrenderer.DocParamNameSubRenderer,
            compound.docSect1TypeSub : compoundrenderer.DocSect1TypeSubRenderer,
            compound.docSimpleSectTypeSub : compoundrenderer.DocSimpleSectTypeSubRenderer,

def parse(self, project_info):

        filename = self.path_handler.join(project_info.path(), "index.xml")

        try: 
            # Try to get from our cache
            return self.cache[filename]
        except KeyError:

            # If that fails, parse it afresh
            try:
                result = breathe.parser.doxygen.index.parse(filename)
                self.cache[filename] = result
                return result
            except breathe.parser.doxygen.index.ParseError:
                raise ParserError(filename)

def create_factory(self, project_info, document):

        renderers = {
            index.DoxygenTypeSub : indexrenderer.DoxygenTypeSubRenderer,
            index.CompoundTypeSub : CreateCompoundTypeSubRenderer(self.parser_factory),
            compound.DoxygenTypeSub : compoundrenderer.DoxygenTypeSubRenderer,
            compound.compounddefTypeSub : compoundrenderer.CompoundDefTypeSubRenderer,
            compound.sectiondefTypeSub : compoundrenderer.SectionDefTypeSubRenderer,
            compound.memberdefTypeSub : compoundrenderer.MemberDefTypeSubRenderer,
            compound.linkedTextTypeSub : compoundrenderer.LinkedTextTypeSubRenderer,
            compound.descriptionTypeSub : compoundrenderer.DescriptionTypeSubRenderer,
            compound.paramTypeSub : compoundrenderer.ParamTypeSubRenderer,
            compound.docRefTextTypeSub : compoundrenderer.DocRefTextTypeSubRenderer,
            compound.docParaTypeSub : compoundrenderer.DocParaTypeSubRenderer,
            compound.docParamListTypeSub : compoundrenderer.DocParamListTypeSubRenderer,
            compound.docParamListItemSub : compoundrenderer.DocParamListItemSubRenderer,
            compound.docParamNameListSub : compoundrenderer.DocParamNameListSubRenderer,
            compound.docParamNameSub : compoundrenderer.DocParamNameSubRenderer,
            compound.docSect1TypeSub : compoundrenderer.DocSect1TypeSubRenderer,
            compound.docSimpleSectTypeSub : compoundrenderer.DocSimpleSectTypeSubRenderer,
            compoundsuper.MixedContainer : compoundrenderer.MixedContainerRenderer,

self.file_state_cache.update(filename)

        try: 
            # Try to get from our cache
            return self.cache[filename]
        except KeyError:

            # If that fails, parse it afresh
            try:
                result = breathe.parser.doxygen.index.parse(filename)
                self.cache[filename] = result
                return result
            except breathe.parser.doxygen.index.ParseError, e:
                raise ParserError(e, filename)
            except breathe.parser.doxygen.index.FileIOError, e:
                raise FileIOError(e, filename)