class CreatePurchase(Wizard):
    'Create Purchase'
    __name__ = 'purchase.request.create_purchase'
    start = StateTransition()
    ask_party = StateView('purchase.request.create_purchase.ask_party',
        'purchase_request.purchase_request_create_purchase_ask_party', [
            Button('Cancel', 'end', 'tryton-cancel'),
            Button('Continue', 'start', 'tryton-go-next', default=True),
            ])

    def transition_start(self):