code: def run(self):
          
          print('Yala is running. It may take several seconds...')
          try:
              check_call('yala setup.py tests kytos', shell=True)
              print('No linter error found.')
          except CalledProcessError:
              print('Linter check failed. Fix the error(s) above and try again.')
              sys.exit(-1)
docs: Run yala.