syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"\"cast({:?})"}]}
source_snippet:                     "cast({:?}) has ty w/ hir_id {:?} and user provided ty {:?}",
context_before:                 debug!(
context_after:                     expr, cast_ty.hir_id, user_ty,