syntax_data: {"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // Only return something if it doesn't overlap with the original span,
context_before:         match Span::prepare_to_combine(self, within) {
context_after:             // and the span isn't "imported" (i.e. from unavailable sources).