syntax_data: {"ast_node_type":"other","tokens":[{"end":17,"kind":"keyword","start":0,"text":"{"}]}
source_snippet:                 {
context_before:                         .contains(&tcx.item_name(trait_item_id))
context_after:                     // For compiler developers who'd like to add new items to `Fn`/`FnMut`/`FnOnce`,