def _push_tag_buffer(self, data):
        """Write a pending tag attribute from *data* to the stack."""
        if data.context & data.CX_QUOTED:
            self._emit_first(tokens.TagAttrQuote(char=data.quoter))
            self._emit_all(self._pop())
        buf = data.padding_buffer
        self._emit_first(tokens.TagAttrStart(
            pad_first=buf["first"], pad_before_eq=buf["before_eq"],
            pad_after_eq=buf["after_eq"]))
        self._emit_all(self._pop())
        for key in data.padding_buffer:
            data.padding_buffer[key] = ""
Write a pending tag attribute from *data* to the stack.