docs: def run(self):
          '''
          Runs all enabled tests.
          '''
          # Run all tests.
          for cls in self.get_test_classes():
  
              # Print informational message.
              self.logger.info('Running {cls.__name__} test...'.format(cls=cls))
  
              # Create new test instance.
              test = cls(runner=self)
  
              # Run test and evaluate result.
              if test._run():
                  self.logger.passed('Test {cls.__name__} succeeded!'.format(cls=cls))
              else:
                  self.logger.failed('Test {cls.__name__} failed!'.format(cls=cls))
                  self.has_passed = False
  
          # Print summary.
          if self.has_passed:
              self.logger.passed('Summary: All tests passed!')
          else:
              self.logger.failed('Summary: One or more tests failed!')
  
          return self.has_passed