syntax_data: {"ast_node_type":"function","tokens":[{"end":67,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn default_from_rustc_driver_dll() -> Result<PathBuf, String> {
context_before: pub(crate) fn default_sysroot() -> PathBuf {
context_after:         let dll = current_dll_path()?;