syntax_data: {"ast_node_type":"variable","tokens":[{"end":59,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let suffix = &chain_refutabilities[from + 1..];
context_before:             // The chain has a non-empty suffix of irrefutable `let` statements
context_after:             let span_start = suffix[0].unwrap().0;