syntax_data: {"ast_node_type":"function","tokens":[{"end":99,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn try_metavars(a: SpanData, b: SpanData, a_orig: Span, b_orig: Span) -> (SpanData, SpanData) {
context_before:     /// Check if you can select metavar spans for the given spans to get matching contexts.
context_after:         match with_metavar_spans(|mspans| (mspans.get(a_orig), mspans.get(b_orig))) {