syntax_data: {"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: /// from another crate's metadata - since `ExpnHash` includes the stable crate id,
context_before: /// `set_expn_data`). It is *not* called for foreign `ExpnId`s deserialized
context_after: /// collisions are only possible between `ExpnId`s within the same crate.