Braintree\SubscriptionSearch::planId PHP Method

    public static function planId()
    {
        return new MultipleValueOrTextNode('plan_id');
    }

 public function test_noRequestsWhenIterating()
 {
     $resultsReturned = false;
     $collection = Braintree\Subscription::search([Braintree\SubscriptionSearch::planId()->is('imaginary')]);
     foreach ($collection as $transaction) {
         $resultsReturned = true;
         break;
     }
     $this->assertSame(0, $collection->maximumCount());
     $this->assertEquals(false, $resultsReturned);
 }