syntax_data: {"ast_node_type":"other","tokens":[{"end":40,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:                 for pat in pats.iter() {
context_before:                 print_indented!(self, "pats: [", depth_lvl + 2);
context_after:                     self.print_pat(pat, depth_lvl + 3);