docs: async def _send_text(self, request: Request, stack: Stack):
          """
          Send text layers to the user. Each layer will go in its own bubble.
  
          Also, Facebook limits messages to 320 chars, so if any message is
          longer than that it will be split into as many messages as needed to
          be accepted by Facebook.
          """
  
          parts = []
  
          for layer in stack.layers:
              if isinstance(layer, lyr.MultiText):
                  lines = await render(layer.text, request, multi_line=True)
                  for line in lines:
                      for part in wrap(line, 320):
                          parts.append(part)
              elif isinstance(layer, (lyr.Text, lyr.RawText)):
                  text = await render(layer.text, request)
                  for part in wrap(text, 320):
                      parts.append(part)
  
          for part in parts[:-1]:
              await self._send(request, {
                  'text': part,
              }, stack)
  
          part = parts[-1]
  
          msg = {
              'text': part,
          }
  
          await self._add_qr(stack, msg, request)
          await self._send(request, msg, stack)