syntax_data: {"ast_node_type":"variable","tokens":[{"end":37,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let i = match region.kind() {
context_before:     fn print_region(&mut self, region: ty::Region<'_>) -> Result<(), PrintError> {
context_after:             // Erased lifetimes use the index 0, for a