syntax_data: {"ast_node_type":"variable","tokens":[{"end":54,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let mut projection = base.projection.to_vec();
context_before:         let base = self.tcx.mk_place_downcast_unnamed(self_place, variant_index);
context_after:         projection.push(ProjectionElem::Field(idx, ty));