syntax_data: {"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //! - The `TypeVisitable` impls handle most of the traversal, and call into
context_before: //! custom visit operations that are specific to the visitor.
context_after: //!   `TypeVisitor` when they encounter a type of interest.