syntax_data: {"ast_node_type":"other","tokens":[{"end":80,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// and the depth of the trait predicate *above* that well-formed predicate.
context_before:     /// will have a perf effect. The value here is the well-formed `GenericArg`
context_after:     wf_args: RefCell<Vec<(ty::Term<'tcx>, usize)>>,