  Many code changes that developers make in their projects are repeated and
constitute recurrent change patterns. It is of interest to collect such
patterns from the version history of open-source repositories and suggest the
most useful of them as quick fixes. In this paper, we present Revizor - a tool
aimed to build custom plugins for PyCharm, a popular Python IDE. A
Revizor-based plugin can take change patterns and highlight potential places
for their application in the developer's code editor. If the developer accepts
the quick fix, the plugin automatically performs the edit. Our approach uses a
graph-based representation of code changes, which allows it to support complex
distributed code patterns. Experienced developers have also rated the usability
and the performance of such Revizor-based plugin positively.
  The source code of the tool and test plugin prototype are available on
GitHub: https://github.com/JetBrains-Research/revizor. A demonstration video
with a short tool description can be found on YouTube:
https://youtu.be/5eLs14nco7E.
