syntax_data: {"ast_node_type":"other","tokens":[{"end":38,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:         for ws in &[" ", "\t", "\n"] {
context_before:         let prev_source = self.span_to_prev_source(sp).ok()?;
context_after:             let pat = pat.to_owned() + ws;