def __missing__(self, key):
        if self.default_factory is None:
            raise KeyError(key)
        else:
            ret = self[key] = self.default_factory(name=key)
            return ret
def downloadNewsPage(self, strTagName=None):
        if strTagName is None:
            #未指定 tag
            lstStrObtainedTagName = self.db.fetchallCompletedObtainedTagName()
            for strObtainedTagName in lstStrObtainedTagName:
                self.downloadNewsPageWithGivenTagName(strTagName=strObtainedTagName)
        else:
            #有指定 tag 名稱
            self.downloadNewsPageWithGivenTagName(strTagName=strTagName)