syntax_data: {"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// It's a cut-down version of `data_untracked`.
context_before:     /// This function is used as a fast path when decoding the full `SpanData` is not necessary.
context_after:     #[cfg_attr(not(test), rustc_diagnostic_item = "SpanCtxt")]