syntax_data: {"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"RustcPatCtxt"}]}
source_snippet:     RustcPatCtxt as PatCtxt, Usefulness, UsefulnessReport, WitnessPat,
context_before:     Constructor, DeconstructedPat, MatchArm, RedundancyExplanation, RevealedTy,
context_after: };