code: def test_grades(self):
      def grade(score, breakpoints=[60, 70, 80, 90], grades="FDCBA"):
          i = self.module.bisect(breakpoints, score)
          return grades[i]
  
      result = [grade(score) for score in [33, 99, 77, 70, 89, 90, 100]]
      self.assertEqual(result, ["F", "A", "C", "C", "B", "A", "A"])
  
imports: import sys
  import unittest
  from test.support import import_helper
  from collections import UserList
label_desc: Use image node_id 1 for calling the TestDocExample obj's underlying member method code with example usage: obj.test_grades() and returns: grades