syntax_data: {"ast_node_type":"other","tokens":[{"end":100,"kind":"keyword","start":0,"text":"assert_eq!(expn_data.disambiguator,"}]}
source_snippet:     assert_eq!(expn_data.disambiguator, 0, "Already set disambiguator for ExpnData: {expn_data:?}");
context_before:     // This disambiguator should not have been set yet.
context_after:     assert_default_hashing_controls(&ctx, "ExpnData (disambiguator)");