I am very new to PHP Unit Testing. I am trying to create Unit Test for the following function:

```
    $context = $args[0];

    if (Subscriber::instance()->isSubscriber()) {
        $context['body_class'] .= ' ' . $this->bodyClass;
    }

    return $context;

```

Which is very simple which adds classname in array if User is subscriber. Subscriber is class which has has a static instance method which returns true or false.

so far I have written this but I don't think this is correct:

```
$subscriber = $this->getMockBuilder(Subscriber::class)
    ->disableOriginalConstructor()
    ->setMethods(['isSubscriber'])
    ->getMock();

$subscriber->expects($this->once())
    ->method('isSubscriber')
    ->will($this->returnValue(true));

$this->assertInternalType('bool',$subscriber->isSubscriber());

```

Any help would be appreciated.