syntax_data: {"ast_node_type":"function","tokens":[{"end":52,"kind":"keyword","start":0,"text":"pub"}]}
source_snippet:     pub fn transpose(self) -> Option<Binder<I, T>> {
context_before: impl<I: Interner, T> Binder<I, Option<T>> {
context_after:         let Binder { value, bound_vars } = self;