syntax_data: {"ast_node_type":"other","tokens":[{"end":3,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: ///
context_before: /// because `rustc_index::newtype_index!` reserves the last 256 values for tagging purposes.
context_after: /// Note that `Symbol` cannot directly be a `rustc_index::newtype_index!` because it