syntax_data: {"ast_node_type":"other","tokens":[{"end":40,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                     if receiver_by_ref {
context_before:                     // still take their receiver by ref.
context_after:                         Ty::new_imm_ref(tcx, tcx.lifetimes.re_erased, coroutine_ty)