syntax_data: {"ast_node_type":"variable","tokens":[{"end":74,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let trait_ref = proj.map_bound(|proj| TraitPredicate {
context_before:                     let proj = bound_predicate.rebind(pred);
context_after:                         trait_ref: proj.projection_term.trait_ref(tcx),