syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"Variant"}]}
source_snippet:     Variant { adt_def: ty::AdtDef<'tcx>, variant_index: VariantIdx },
context_before: enum TestCase<'tcx> {
context_after:     Constant { value: mir::Const<'tcx> },