syntax_data: {"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Check if you can select metavar spans for the given spans to get matching contexts.
context_after:     fn try_metavars(a: SpanData, b: SpanData, a_orig: Span, b_orig: Span) -> (SpanData, SpanData) {