syntax_data: {"ast_node_type":"function","tokens":[{"end":51,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub fn get(&self, span: Span) -> Option<Span> {
context_before:     /// Read a span and record that it was read.
context_after:         if let Some(mut mspans) = self.0.try_write() {