{"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":".and_then(|def_id|"}]}
                            .and_then(|def_id| tcx.impl_of_assoc(def_id))
                            .type_dependent_def_id(expr.hir_id)
                            .map(|def_id| tcx.associated_items(def_id))