message: Hide List.content field
  Summary: To modify `List` easier.
diff: @@ -58,7 +58,7 @@ struct ListGen<T>(T);
  #[repr(transparent)]
  pub struct List<'v> {
  /// The data stored by the list.
  - pub content: Vec<Value<'v>>,
  + pub(crate) content: Vec<Value<'v>>,
  }
  /// Define the list type. See [`List`] and [`FrozenList`] as the two possible representations.
  @@ -66,7 +66,7 @@ pub struct List<'v> {
  #[repr(transparent)]
  pub struct FrozenList {
  /// The data stored by the list.
  - pub content: Vec<FrozenValue>,
  + content: Vec<FrozenValue>,
  }
  unsafe impl<'v> AnyLifetime<'v> for ListGen<RefCell<List<'v>>> {
  @@ -199,6 +199,11 @@ impl<'v> List<'v> {
  self.content.len()
  }
  + /// List content.
  + pub fn content(&self) -> &[Value<'v>] {
  + &self.content
  + }
  +
  /// Iterate over the elements in the list.
  pub fn iter<'a>(&'a self) -> impl Iterator<Item = Value<'v>> + 'a
  where
  