syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// takes a `u32` argument instead of a `&self` argument. Use with care.
context_before:     /// Note: this applies to both `Symbol`s and `ByteSymbol`s, which is why it
context_after:     pub fn is_predefined(index: u32) -> bool {