syntax_data: {"ast_node_type":"variable","tokens":[{"end":24,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let this = self;
context_before:     pub(crate) fn as_constant(&mut self, expr: &Expr<'tcx>) -> ConstOperand<'tcx> {
context_after:         let tcx = this.tcx;