code: def config_from_environment():
      
      kwargs = {}
      for k in CONFIG_OPTIONS:
          env = 'TOWER_' + k.upper()
          v = os.getenv(env, None)
          if v is not None:
              kwargs[k] = v
      return kwargs
docs: Read tower-cli config values from the environment if present, being
      careful not to override config values that were explicitly passed in.