syntax_data: {"ast_node_type":"function","tokens":[{"end":41,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub fn surrounding(s: Span) -> Self {
context_before: impl ExprParenthesesNeeded {
context_after:         ExprParenthesesNeeded { left: s.shrink_to_lo(), right: s.shrink_to_hi() }