How can I call a method, from another method of the same class and of different classes, according to a condition. use several codes (#) but none of them executes the conditions methods.

@api.multi

    def action_crear_documento1(self):

        if self.type=="sale":

            if self.invoice_type_code_id=="08":

                self.pool.get('account.journal').action_boleta_venta1(self)

                #journal=self.env['account.journal']

                #journal.action_boleta_venta1()

            elif self.invoice_type_code_id=="01":

                self.pool.get('account.journal').action_boleta_venta1(self)

                #journal=self.env['account.journal']

                #journal.action_boleta_venta1()

                #return self.action_boleta_venta4

    @api.multi

    def action_boleta_venta4(self):

        #code

    @api.multi

    def action_boleta_venta3(self):

        #code