syntax_data: {"ast_node_type":"other","tokens":[{"end":41,"kind":"keyword","start":0,"text":"Constant"}]}
source_snippet:     Constant { value: mir::Const<'tcx> },
context_before:     Variant { adt_def: ty::AdtDef<'tcx>, variant_index: VariantIdx },
context_after:     Range(Arc<PatRange<'tcx>>),