brettviren/transfer-api-client-python — comment on commit a50b188d0888711c71f8e8f31fd254c7a25bf852
File: globusonline/transfer/api_client/verified_https.py line 55
By bd4:

set_tunnel was added in 2.7. In 2.6.6, it's called _set_tunnel and isn't part of the public API, but may still be usable. In 2.6.1 it doesn't exist at all. This could be handled like this:
if hasattr(self, "set_tunnel"):
self.set_tunnel(real_host, real_port)
elif hasattr(self, "_set_tunnel"):
self._set_tunnel(real_host, real_port)