rust: setters for an embed

[problame]

struct Foo {
  id: i32,
  .. FooData
}

struct FooData {
  foo: str,
  bar: str
}

should render

struct Foo { ...}
struct FooData { ... }

impl Foo {
  pub fn set_foo_data(&mut self, data: FooData) {
    self.foo = data.foo;
    self.bar = data.bar;
  }
}