syntax_data: {"ast_node_type":"other","tokens":[{"end":26,"kind":"keyword","start":0,"text":"None"}]}
source_snippet:             None => false,
context_before:         let in_self_mod = match characteristic_def_id_of_type(self_ty) {
context_after:             Some(ty_def_id) => self.tcx().parent(ty_def_id) == parent_def_id,