syntax_data: {"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"\"metadata"}]}
source_snippet:         "metadata to mangle symbol names with"),
context_before:     metadata: Vec<String> = (Vec::new(), parse_list, [TRACKED],
context_after:     no_prepopulate_passes: bool = (false, parse_no_value, [TRACKED],