syntax_data: {"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // Pushing a base user type always causes the chain to become non-empty.
context_before:     pub(crate) fn push_user_type(&'a self, base: UserTypeAnnotationIndex) -> Self {
context_after:         Self::Chain { parent: self, op: ProjectedUserTypesOp::PushUserType { base } }