public function testConstructor()
{
$payload = new \stdClass();
$message1 = new GenericCommandMessage($payload);
$metaDataMap = array("key" => "value");
$metaData = new MetaData($metaDataMap);
$message2 = new GenericCommandMessage($payload, $metaData);
$this->assertSame(MetaData::emptyInstance(), $message1->getMetaData());
$this->assertEquals('stdClass', get_class($message1->getPayload()));
$this->assertEquals('stdClass', $message1->getPayloadType());
$this->assertSame($metaData, $message2->getMetaData());
$this->assertEquals('stdClass', get_class($message2->getPayload()));
$this->assertEquals('stdClass', $message2->getPayloadType());
$this->assertFalse($message1->getIdentifier() === $message2->getIdentifier());
}
