code: def file(self, path, status=200, set_content_length=True):
          
          ct, encoding = mimetypes.guess_type(path)
          if not ct:
              ct = 'application/octet-stream'
          if encoding:
              self.headers[aiohttp.hdrs.CONTENT_ENCODING] = encoding
          self.content_type = ct
  
          if set_content_length:
              st = os.stat(path)
              self.last_modified = st.st_mtime
              self.headers[aiohttp.hdrs.CONTENT_LENGTH] = str(st.st_size)
          else:
              self.enable_chunked_encoding()
  
          self.set_status(status)
  
          try:
              with open(path, 'rb') as fobj:
                  yield from self.prepare(self._request)
  
                  while True:
                      data = fobj.read(4096)
                      if not data:
                          break
                      yield from self.write(data)
                      yield from self.drain()
  
          except FileNotFoundError:
              raise aiohttp.web.HTTPNotFound()
          except PermissionError:
              raise aiohttp.web.HTTPForbidden()
docs: Return a file as a response