syntax_data: {"ast_node_type":"other","tokens":[{"end":61,"kind":"keyword","start":0,"text":"ty::Param(ref"}]}
source_snippet:             ty::Param(ref param_ty) => param_ty.print(self)?,
context_before:             ty::Error(_) => write!(self, "{{type error}}")?,
context_after:             ty::Bound(debruijn, bound_ty) => match bound_ty.kind {