syntax_data: {"ast_node_type":"variable","tokens":[{"end":60,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let line_bounds = self.file.line_bounds(line_index);
context_before:         let line_index = self.file.lookup_line(pos).unwrap();
context_after:         self.line_number = line_index + 1;