lib/base.js
function (keys) {
    var Parent = this.constructor;
    var opts = lazy.clone(this.options);
    var res = new Parent(opts);

    lazy.omit(this, keys, function (val, key) {
      res[key] = lazy.clone(val);
    });
    return res;
  }
function (keys) {
    var Parent = this.constructor;
    var opts = lazy.clone(this.options);
    var res = new Parent(opts);

    lazy.omit(this, keys, function (val, key) {
      res[key] = lazy.clone(val);
    });
    return res;
  }
function ( keys ) { var Parent = this . constructor ; var opts = lazy . clone ( this . options ) ; var res = new Parent ( opts ) ; lazy . omit ( this , keys , function ( val , key ) { res [ key ] = lazy . clone ( val ) ; } ) ; return res ; }
Return a clone of the instance.

```js
var foo = app.clone();
```
@param  {Array} keys Optionally pass an array of keys to omit.
@return {Object}
@api public
Return a clone of the instance .