syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"bug!(\"{:?}"}]}
source_snippet:                     bug!("{:?} not found in {:?}", trait_item_id, impl_data.impl_def_id);
context_before:                 .unwrap_or_else(|| {
context_after:                 });