syntax_data: {"ast_node_type":"other","tokens":[{"end":53,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// creating an extra copy of the dataflow state.
context_before:     /// This can be used, e.g., to apply the call return effect directly to the cursor without
context_after:     pub fn apply_custom_effect(&mut self, f: impl FnOnce(&mut A, &mut A::Domain)) {