multi line assertion function replaced with invalid code

Consider the following code:

import unittest


class Tests(unittest.TestCase):
    def test_1(self):
        self.assertIn('multline line assert',
                      'multline line assert')

This is the output:

import unittest


class Tests(unittest.TestCase):
    def test_1(self):
        assert 'multline line assert' in
                      'multline line assert'

This is the correct output:

import unittest


class Tests(unittest.TestCase):
    def test_1(self):
        assert 'multline line assert' in 'multline line assert'

Reproduce the issue with the unittest snippet in the report and compare the invalid output with the expected output. Find the conversion handling for multiline assertIn calls; done means the generated assertion is valid Python and keeps both operands on the same line as shown.