code: function extend(src) {
    var obj, args = arguments;
    for (var i = 1; i < args.length; ++i) {
      if (obj = args[i]) {
        for (var key in obj) {
          // check if this property of the source object could be overridden
          if (isWritable(src, key))
            { src[key] = obj[key]; }
        }
      }
    }
    return src
  }
docs: Extend any object with other properties
  @param   { Object } src - source object
  @returns { Object } the resulting extended object
  
  var obj = { foo: 'baz' }
  extend(obj, {bar: 'bar', foo: 'bar'})
  console.log(obj) => {bar: 'bar', foo: 'bar'}