Method defaults

src/utils.ts:421–436

(target, ...sources)

   */
  // eslint-disable-next-line
  static defaults(target, ...sources): {} {

    sources.forEach(source => {
      for (const key in source) {
        if (!source.hasOwnProperty(key)) return;
        if (target[key] === null || target[key] === undefined) {
          target[key] = source[key];
        } else if (typeof source[key] === 'object' && typeof target[key] === 'object') {
          // property is an object, recursively add it's field over... #1373
          Utils.defaults(target[key], source[key]);
        }
      }
    });

    return target;
  }

  /**
   * Compare two objects for equality (shallow comparison).