thinkphp Vender importing third-party class libraries

Third-party class library files: F:\xampp\htdocs\Cms\Extend\Vendor\snoopy.php
The custom classes are as follows:

class Sms extends UserAction{    vendor('Snoopy');    public function sms(){    .....    }}

Operation is an error as follows:

Excuse me, what is the reason, my writing is not wrong ah, how to change, first thank you!

Reply content:

Third-party class library files:F:\xampp\htdocs\Cms\Extend\Vendor\snoopy.php
The custom classes are as follows:

class Sms extends UserAction{    vendor('Snoopy');    public function sms(){    .....    }}

Operation is an error as follows:

Excuse me, what is the reason, my writing is not wrong ah, how to change, first thank you!

vendor('Snoopy');class Sms extends UserAction{}

class Sms extends UserAction{    public function sms(){        vendor('Snoopy');    }}

