syntax_data: {"ast_node_type":"other","tokens":[{"end":95,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Returns `Some(span)`, a union of the LHS and RHS span. The LHS must precede the RHS. If
context_before: impl SourceMap {
context_after:     /// there are gaps between LHS and RHS, the resulting union will cross these gaps.