code: def receive(
              self,
              request: RequestType,
              user: UserType = None,
              sender_key_fetcher: Callable[[str], str] = None,
              skip_author_verification: bool = False) -> Tuple[str, str]:
          
          self.user = user
          self.get_contact_key = sender_key_fetcher
          self.store_magic_envelope_doc(request.body)
          # Open payload and get actual message
          self.content = self.get_message_content()
          # Get sender handle
          self.sender_handle = self.get_sender()
          # Verify the message is from who it claims to be
          if not skip_author_verification:
              self.verify_signature()
          return self.sender_handle, self.content
docs: Receive a payload.
  
          For testing purposes, `skip_author_verification` can be passed. Authorship will not be verified.