code: func (F *Frisby) AfterContent(foo AfterContentFunc) *Frisby {
  	content, err := F.Resp.Content()
  	foo(F, content, err)
  	return F
  }
docs: // AfterContent 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 AfterContentFunc
  //  type AfterContentFunc func(F *Frisby, content []byte, err error)
  //