code: func (F *Frisby) AfterJson(foo AfterJsonFunc) *Frisby {
  	json, err := F.Resp.Json()
  	foo(F, json, err)
  	return F
  }
docs: // AfterJson allows you to write your own functions for inspecting the body of the response.
  // You are also provided with the Frisby object.
  //
  // The function signiture is AfterJsonFunc
  //  type AfterJsonFunc func(F *Frisby, json *simplejson.Json, err error)
  //
  // simplejson docs: https://github.com/bitly/go-simplejson