syntax_data: {"ast_node_type":"variable","tokens":[{"end":49,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let end_index = local_end.pos.to_usize();
context_before:         let start_index = local_begin.pos.to_usize();
context_after:         debug!("start_index=`{:?}`, end_index=`{:?}`", start_index, end_index);