[tests] Just a lone leftover...

tests/PHPUnit/PredisTestCase.php

@@ -39,16 +39,6 @@ abstract class PredisTestCase extends \PHPUnit\Framework\TestCase
         usleep($seconds * 1000000);
     }
 
-    /**
-     * Indicates if the current runtime is HHVM.
-     *
-     * @return bool
-     */
-    protected function isHHVM(): bool
-    {
-        return defined('HHVM_VERSION');
-    }
-
     /**
      * Verifies that a Redis command is a valid Predis\Command\CommandInterface
      * instance with the specified ID and command arguments.