def f1_debug_output(self, debug: Iterable[str]) -> str:
        """Runs some code with `debug` option, returns the debug output."""
        # Make code to run.
        self.make_file("f1.py", """\
            def f1(x):
                return x+1

            for i in range(5):
                f1(i)
            """)

        debug_out = io.StringIO()
        cov = coverage.Coverage(debug=debug)
        cov._debug_file = debug_out
        self.start_import_stop(cov, "f1")
        cov.save()

        return debug_out.getvalue()
Runs some code with `debug` option, returns the debug output.
tests/test_debug.py