mpyw\Co\Internal\TypeUtils::isGeneratorContainer PHP Method

    public static function isGeneratorContainer($value)
    {
        return $value instanceof GeneratorContainer;
    }

 public function testIsGeneratorContainer()
 {
     $gen = (function () {
         (yield 1);
     })();
     $con = new GeneratorContainer($gen);
     $this->assertTrue(TypeUtils::isGeneratorContainer($con));
     $this->assertFalse(TypeUtils::isGeneratorContainer($gen));
 }