syntax_data: {"ast_node_type":"other","tokens":[{"end":85,"kind":"keyword","start":0,"text":"\"emit"}]}
source_snippet:         "emit compiler diagnostics in a form suitable for UI testing (default: no)"),
context_before:     ui_testing: bool = (false, parse_bool, [UNTRACKED],
context_after:     uninit_const_chunk_threshold: usize = (16, parse_number, [TRACKED],