syntax_data: {"ast_node_type":"function","tokens":[{"end":94,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub fn span_extend_to_prev_char(&self, sp: Span, c: char, accept_newlines: bool) -> Span {
context_before:     /// if no character could be found or if an error occurred while retrieving the code snippet.
context_after:         if let Ok(prev_source) = self.span_to_prev_source(sp) {