code: async function parseDocument(rawData) {
    try {
      return utils.unthrowableParseJson(rawData) || SwaggerParser.YAML.parse(rawData);
    } catch (err) {
      return null;
    }
  }
docs: Parse string data into swagger 2.0 object (https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#swagger-object)
  
  @param {string} rawData
  
  @returns {Object|null} Swagger 2.0 object