syntax_data: {"ast_node_type":"variable","tokens":[{"end":54,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let trait_bound_vars = trait_ref.bound_vars();
context_before:         let pred_bound_vars = bound_pred.bound_vars();
context_after:         // 1) Self: Bar1<'a, '^0.0> -> Self: Bar1<'a, '^0.1>