syntax_data: {"ast_node_type":"variable","tokens":[{"end":63,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let source_len: RelativeBytePos = Decodable::decode(d);
context_before:         let checksum_hash: Option<SourceFileHash> = Decodable::decode(d);
context_after:         let lines = {