code: def validate_json(self):
          
          if not hasattr(self, 'guidance_json'):
              return False
  
          checksum = self.guidance_json.get('checksum')
          contents = self.guidance_json.get('db')
  
          hash_key = ("{}{}".format(json.dumps(contents, sort_keys=True),
                                    self.assignment.endpoint).encode())
  
          digest = hashlib.md5(hash_key).hexdigest()
  
          if not checksum:
              log.warning("Checksum on guidance not found. Invalidating file")
              return False
          if digest != checksum:
              log.warning("Checksum %s did not match actual digest %s", checksum, digest)
              return False
          return True
docs: Ensure that the checksum matches.