syntax_data: {"ast_node_type":"variable","tokens":[{"end":39,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let result = width.truncate(n);
context_before:         trace!("trunc {} with size {} and shift {}", n, width.bits(), 128 - width.bits());
context_after:         trace!("trunc result: {}", result);