@child

@child("kind") declares a field that holds a single nested block of the given kind. Make the field optional (Type?) when the child may be omitted. Contrast with @children, which holds a list.

@block("service") type Service {
  @child("metadata") meta: Metadata?
}

@block("metadata") type Metadata {
  owner: utf8
}

service api {
  metadata { owner = "platform" }
}