syntax_data: {"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                         if !seen_late.insert((di, reg)) {
context_before:                     (CheckRegions::FromFunction, ty::ReBound(di, reg)) => {
context_after:                             return Err(NotUniqueParam::DuplicateParam(lt.into()));