v3.5.0 has no exist_friendship method.
:rtype: :class:`User` object
-.. method:: API.exists_friendship(user_a, user_b)
-
- Checks if a friendship exists between two users. Will return True if
- user_a follows user_b, otherwise False.
-
- :param user_a: The ID or screen_name of the subject user.
- :param user_b: The ID or screen_name of the user to test for following.
- :rtype: True/False
-
-
.. method:: API.show_friendship(source_id/source_screen_name, target_id/target_screen_name)
Returns detailed information about the relationship between two users.