## Feature <!-- What Python feature is missing from RustPython? Give a short description of the feature and how you ran into its absence. --> required by recent version of `doctest` ## Python Documentation <!-- Give a link to the feature in the CPython documentation (https://docs.python.org/3/) in order to assist in its implementation. --> https://docs.python.org/3/library/io.html#io.IncrementalNewlineDecoder