code: def detect_old(data):
      "Check for a config file with old schema"
      if not data:
          return False
      ok, errors, warnings = _schema.validate(_OLD_SCHEMA, data)
      return ok and not (errors or warningsf detect_old(data):
      "Check for a config file with old schema"
      if not data:
          return False
      ok, errors, warnings = _schema.validate(_OLD_SCHEMA, data)
      return ok and not (errors or warnings)
docs: Check for a config file with old schema