PayU\Configuration::getMerchantId PHP Method

    public function getMerchantId()
    {
        return $this->merchantId;
    }

 public function testSetMerchantId()
 {
     $this->configuration->setMerchantId('TestMerchantIdSetter');
     $this->assertEquals('TestMerchantIdSetter', $this->configuration->getMerchantId());
 }