syntax_data: {"ast_node_type":"function","tokens":[{"end":72,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn from_flat_pat(flat_pat: FlatPat<'tcx>, has_guard: bool) -> Self {
context_before:     /// Incorporates an already-simplified [`FlatPat`] into a new candidate.
context_after:         let mut this = Candidate {