docs: def _finish_init(self, client, entities, input_chat):
          """
          Finishes the initialization of this message by setting
          the client that sent the message and making use of the
          known entities.
          """
          self._client = client
          self._sender = entities.get(self._sender_id)
          if self._sender:
              try:
                  self._input_sender = utils.get_input_peer(self._sender)
              except TypeError:
                  self._input_sender = None
  
          self._chat = entities.get(self.chat_id)
          self._input_chat = input_chat
          if not self._input_chat and self._chat:
              try:
                  self._input_chat = utils.get_input_peer(self._chat)
              except TypeError:
                  self._input_chat = None
  
          self._via_bot = entities.get(self.via_bot_id)
          if self._via_bot:
              try:
                  self._via_input_bot = utils.get_input_peer(self._via_bot)
              except TypeError:
                  self._via_input_bot = None
  
          if self.fwd_from:
              self._forward = Forward(self._client, self.fwd_from, entities)
  
          if self.action:
              if isinstance(self.action, (types.MessageActionChatAddUser,
                                          types.MessageActionChatCreate)):
                  self._action_entities = [entities.get(i)
                                           for i in self.action.users]
              elif isinstance(self.action, types.MessageActionChatDeleteUser):
                  self._action_entities = [entities.get(self.action.user_id)]
              elif isinstance(self.action, types.MessageActionChatJoinedByLink):
                  self._action_entities = [entities.get(self.action.inviter_id)]
              elif isinstance(self.action, types.MessageActionChatMigrateTo):
                  self._action_entities = [entities.get(utils.get_peer_id(
                      types.PeerChannel(self.action.channel_id)))]
              elif isinstance(
                      self.action, types.MessageActionChannelMigrateFrom):
                  self._action_entities = [entities.get(utils.get_peer_id(
                      types.PeerChat(self.action.chat_id)))]