syntax_data: {"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"last.nested_goals.insert(last.input,"}]}
source_snippet:         last.nested_goals.insert(last.input, PathsToNested::EMPTY);
context_before:         last.nested_goals.insert(input, step_kind_from_parent.into());
context_after:         if last_index != head {