syntax_data: {"ast_node_type":"other","tokens":[{"end":41,"kind":"keyword","start":0,"text":"sig.to_coroutine("}]}
source_snippet:                         sig.to_coroutine(
context_before:                         [self_ty].into_iter().chain(sig.tupled_inputs_ty.tuple_fields()).collect(),
context_after:                             tcx,