python3-defer 1.0.6-2build1 (amd64 binary) in ubuntu eoan

 The defer module provides an easy way to write asynchrouns Python 3 programs.
 It is greatly inspired by Twisted's defer, but hasn't got any external
 dependencies.
 .
 Furthermore it features decorators to write asynchronous D-Bus servers and
 clients.
 .
 At first defer was part of aptdaemon, but moved to a separate project in
 August of 2010.