syntax_data: {"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"Ok(src.get(start_index..end_index).is_some())"}]}
source_snippet:             Ok(src.get(start_index..end_index).is_some())
context_before:         self.span_to_source(sp, |src, start_index, end_index| {
context_after:         })