syntax_data: {"ast_node_type":"impl","tokens":[{"end":41,"kind":"keyword","start":0,"text":"impl"}]}
source_snippet:             impl DepTrackingHash for $t {
context_before:         ($($t:ty),+ $(,)?) => {$(
context_after:                 fn hash(&self, hasher: &mut StableHasher, _: ErrorOutputType, _for_crate_hash: bool) {