syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"e.span_label(span,"}]}
source_snippet:                         e.span_label(span, "constant depends on this generic parameter");
context_before:                         let span = self.tcx.def_span(param.def_id);
context_after:                         if let Some(ident) = self.tcx.def_ident_span(def_id)