Bonsai.Optionval wrap_model :
?on_action_for_none:(unit, 'model option) on_action_mismatch ->
('input, 'model, 'result) t ->
('input, 'model option, 'result option) tval wrap_model_with_default :
?on_action_for_none:(unit, 'model option) on_action_mismatch ->
('input, 'model, 'result) t ->
default:'result ->
('input, 'model option, 'result) t