code: def verify(self):
          
          if any(not i for i in (self.chat_uid, self.module_id)):
              raise ValueError("Chat data is incomplete.")
          if not isinstance(self.chat_type, ChatType):
              raise ValueError("Invalid chat type.")
          if self.chat_type == ChatType.Group:
              if any(not isinstance(i, EFBChat) or not i.chat_type == ChatType.User for i in self.members):
                  raise ValueError("The group has an invalid member.")
          if self.group is not None and (not isinstance(self.group, EFBChat) or
                                         not self.group.chat_type == ChatType.Group):
              raise ValueError("The member is in an invalid group.")
docs: Verify the completeness of the data.
  
          Raises:
              ValueError: When this chat is invalid.