How to use the autopep8.find_newline function in autopep8

def test_find_newline_only_lf(self):
        source = ['print 1\n', 'print 2\n', 'print3\n']
        self.assertEqual(autopep8.LF, autopep8.find_newline(source))

def test_find_newline_cr1_and_crlf2(self):
        source = ['print 1\r\n', 'print 2\r', 'print3\r\n']
        self.assertEqual(autopep8.CRLF, autopep8.find_newline(source))

def test_find_newline_should_default_to_lf(self):
        self.assertEqual(autopep8.LF, autopep8.find_newline([]))
        self.assertEqual(autopep8.LF, autopep8.find_newline(['', '']))

def test_find_newline_cr1_and_lf2(self):
        source = ['print 1\n', 'print 2\r', 'print3\n']
        self.assertEqual(autopep8.LF, autopep8.find_newline(source))

def test_find_newline_only_crlf(self):
        source = ['print 1\r\n', 'print 2\r\n', 'print3\r\n']
        self.assertEqual(autopep8.CRLF, autopep8.find_newline(source))

def test_find_newline_only_cr(self):
        source = ['print 1\r', 'print 2\r', 'print3\r']
        self.assertEqual(autopep8.CR, autopep8.find_newline(source))