syntax_data: {"ast_node_type":"variable","tokens":[{"end":67,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let var = ty::BoundVar::from_usize(vars.len());
context_before:                     assert_eq!(re, tcx.lifetimes.re_erased);
context_after:                     vars.push(ty::BoundVariableKind::Region(ty::BoundRegionKind::Anon));