code: function _extend (dst, ...sources) {
    if (dst && sources) {
      for (let src of sources) {
        if (typeof src === 'object') {
          Object.getOwnPropertyNames(src).forEach(function (key) {
            dst[key] = src[key];
          });
        }
      }
    }
  
    return dst;
  }
docs: Extend given object's with other objects' properties, overriding existing ones if necessary