syntax_data: {"ast_node_type":"other","tokens":[{"end":60,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:                 for arg in args.iter().rev().skip(1).rev() {
context_before:                 write!(f, "({:?}: {:?})(", func, func_ty)?;
context_after:                     write!(f, "{:?}, ", arg)?;