Method truncate

Lib/test/test_io.py:250–251

(self, *args)

        raise self.UnsupportedOperation("not seekable")

    def truncate(self, *args):
        raise self.UnsupportedOperation("not seekable")

class CMockUnseekableIO(MockUnseekableIO, io.BytesIO):
    UnsupportedOperation = io.UnsupportedOperation