syntax_data: {"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                         // ensure that the `closure_kind` of the resulting closure is in
context_before:                         // always dispatches to the `FnOnce` implementation. This is to
context_after:                         // sync with the built-in trait implementations (since all of the