syntax_data: {"ast_node_type":"other","tokens":[{"end":30,"kind":"keyword","start":0,"text":"\"the"}]}
source_snippet:         "the backend to use"),
context_before:     codegen_backend: Option<String> = (None, parse_opt_string, [TRACKED],
context_after:     contract_checks: Option<bool> = (None, parse_opt_bool, [TRACKED],