syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"Some(principal_def_id)"}]}
source_snippet:             Some(principal_def_id) if !cx.trait_is_auto(principal_def_id) => {
context_before:         ty::Dynamic(trait_info, ..) => match trait_info.principal_def_id() {
context_after:                 Some(SimplifiedType::Trait(principal_def_id))