Avoid relying on .__iter__ to tell iterators apart

.send_file() would fail with stream objects (those from open())
since they are iterable, and asserting that they weren't bytes
or str was not enough.

telethon/events/__init__.py

@@ -14,7 +14,7 @@ def _into_id_set(client, chats):
     if chats is None:
         return None
 
-    if not hasattr(chats, '__iter__') or isinstance(chats, str):
+    if not utils.is_list_like(chats):
         chats = (chats,)
 
     result = set()