'configure command at the ip vpn view'

def config_ip_vpn(self):

    if ((not self.vpn_instance) or (not self.vpn_vni)):
        return
    view_cmd = ('ip    vpn-instance    %s' % self.vpn_instance)
    exist = is_config_exist(self.config, view_cmd)
    if (not exist):
        self.module.fail_json(msg=('Error:    ip    vpn    instance    %s    is    not    exist.' % self.vpn_instance))
    cmd = ('vxlan    vni    %s' % self.vpn_vni)
    exist = is_config_exist(self.config, cmd)
    if ((self.state == 'present') and (not exist)):
        self.cli_add_command(view_cmd)
        self.cli_add_command(cmd)
        self.cli_add_command('quit')
    elif ((self.state == 'absent') and exist):
        self.cli_add_command(view_cmd)
        self.cli_add_command(cmd, undo=True)
        self.cli_add_command('quit')
