syntax_data: {"ast_node_type":"other","tokens":[{"end":95,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // FIXME: extend the AST items to have a head span, or replace callers with pointing at
context_before:     pub fn guess_head_span(&self, sp: Span) -> Span {
context_after:         // the item's ident when appropriate.