syntax_data: {"ast_node_type":"import","tokens":[{"end":79,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //!   impl, because some of the types of interest are recursive and can contain
context_before: //! - A `TypeFolder`/`FallibleTypeFolder` may call into another `TypeFoldable`
context_after: //!   other types of interest.