syntax_data: {"ast_node_type":"other","tokens":[{"end":90,"kind":"keyword","start":0,"text":"local_decls:"}]}
source_snippet:             local_decls: IndexVec::from_elem_n(LocalDecl::new(return_ty, return_span), 1),
context_before:             fixed_temps_scope: None,
context_after:             canonical_user_type_annotations: IndexVec::new(),