>>> client.get_message_history(-1001143136828)
Traceback (most recent call last):
File "messages.py", line 23, in <module>
total, messages, senders = client.get_message_history(-1001143136828)
File "/Users/kosyachniy/anaconda/lib/python3.5/site-packages/telethon/telegram_client.py", line 548, in get_message_history
add_mark=True
KeyError: 1143136828