Returns `chat`, but will make an API call to find the
        chat unless it's already cached.

async def get_chat(self):
        """
        Returns `chat`, but will make an API call to find the
        chat unless it's already cached.
        """
        # See `get_sender` for information about 'min'.
        if (self._chat is None or getattr(self._chat, 'min', None))\
                and await self.get_input_chat():
            try:
                self._chat =\
                    await self._client.get_entity(self._input_chat)
            except ValueError:
                await self._refetch_chat()
        return self._chat