'Return True iff this is a multi-lang language.
I.e. Is this a language that supports embedding of different
programming languages. For example RHTML can have Ruby and
JavaScript content, HTML can have JavaScript content.'

def is_multilang(self, lang):

    try:
        return issubclass(self.buf_class_from_lang[lang], UDLBuffer)
    except KeyError:
        return False
