syntax_data: {"ast_node_type":"other","tokens":[{"end":66,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // not known to hold in the creator's context (and
context_before:                 // like `|x: &'a T|` -- it may be that `T: 'a` is
context_after:                 // indeed the closure may not be invoked by its