def test_normal_formatting(self):
     formatter = SafeFormatter()
     self.assertEqual(formatter.format('{}{{{}}}', 1, 2), '1{2}')
     self.assertEqual(
         formatter.format('{apples}{{{oranges}}}',
                          apples='red',
                          oranges='unicorn'), 'red{unicorn}')
 def test_missing(self):
     formatter = SafeFormatter()
     self.assertEqual(formatter.format('{}'), '{0}')
     self.assertEqual(formatter.format('{cheese}', fruit='pears'),
                      '{cheese}')