syntax_data: {"ast_node_type":"variable","tokens":[{"end":46,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let mut assumed_wf_types: Vec<_> =
context_before:             let liberated_sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), sig);
context_after:                 tcx.assumed_wf_types(tcx.local_parent(def_id)).into();