anchor.diff:   * Automatically create the `fn container()`, `type Msg`, `type Model` and `type Root` items.
    * Automatically insert the call to `Widget::set_property()` in the `update()` function when assigning to an attribute of the model.
    * Automatically create the `Widget` `struct`.
  +
  +To be able to use this attribute, you need to add the `relm-attributes` crate in your `Cargo.toml`:
  +
  +[source,toml]
  +----
  +relm-attributes = "^0.9.0"
  +----
  +
  +and to add the following code:
  +
  +[source,rust]
  +----
  +#![feature(proc_macro)]
  +
  +extern crate relm_attributes;
  +
  +use relm_attributes::widget;
  +----
   
   Here is an example using this attribute:
   
  
positive.code: [source,rust]
  ----
  fn main() {
      relm::run::<Win>().unwrap();
  }
  ----
  
  
negative.code: 
  [source,bash]
  ----
  gtk = "^0.1.2"
  relm = "0.9.6"
  relm-derive = "^0.9.2"
  ----
  
  Next, add this to your crate:
  