syntax_data: {"ast_node_type":"other","tokens":[{"end":95,"kind":"keyword","start":0,"text":"tcx.impl_of_assoc(def_id.to_def_id()).and_then(|def_id|"}]}
source_snippet:             tcx.impl_of_assoc(def_id.to_def_id()).and_then(|def_id| tcx.impl_trait_ref(def_id))
context_before:         && let Some(trait_ref) =
context_after:         && tcx.is_lang_item(trait_ref.instantiate_identity().def_id, LangItem::Drop)