syntax_data: {"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: /// `set_expn_data`). It is *not* called for foreign `ExpnId`s deserialized
context_before: /// with an `ExpnId` (when the `ExpnId` is initially constructed, or via
context_after: /// from another crate's metadata - since `ExpnHash` includes the stable crate id,