lib/classes/Service.js/Service/load
class Service:  load(rawOptions) {
    const that = this;
    const options = rawOptions || {};
    if (!options.stage && options.s) options.stage = options.s;
    if (!options.region && options.r) options.region = options.r;
    const servicePath = this.serverless.config.servicePath;

    // skip if the service path is not found
    // because the user might be creating a new service
    if (!servicePath) {
      return BbPromise.resolve();
    }

    return BbPromise.all([
      serverlessConfigFileUtils.getServerlessConfigFilePath(this.serverless),
      serverlessConfigFileUtils.getServerlessConfigFile(this.serverless),
    ]).then(args => that.loadServiceFileParam(...args));
  }