syntax_data: {"ast_node_type":"other","tokens":[{"end":54,"kind":"keyword","start":0,"text":"foreign_expn_hashes:"}]}
source_snippet:             foreign_expn_hashes: FxHashMap::default(),
context_before:             foreign_expn_data: FxHashMap::default(),
context_after:             expn_hash_to_expn_id: iter::once((ExpnHash(Fingerprint::ZERO), ExpnId::root()))