text: import datetime
  from dataclasses import dataclass
  from typing import Union, List
  
  
  @dataclass
  class SlackInstance:
      name: str
  
      @property
      def url(self):
          return f"{self.name}.slack.com"
  
  @dataclass
  class PrivateConversation:
      member: str
  
  @dataclass
  class Channel:
      name: str
  
  @dataclass
  class GroupConversation:
      members: List[str]
  
  Conversation = Union[PrivateConversation, GroupConversation, Channel]
  
  @dataclass
  class Message:
      slack_instance: SlackInstance
      conversation: Conversation
      author: str
      text: str
      created: datetime.datetime
  