src/Payum/Core/GatewayFactory.php
public function createConfig(array $config = array())
    {
        $config = ArrayObject::ensureArrayObject($config);
        $config->defaults($this->defaultConfig);
        $config->defaults($this->coreGatewayFactory->createConfig((array) $config));

        $this->populateConfig($config);

        return (array) $config;
    }
public function createConfig(array $config = array())
    {
        $config = ArrayObject::ensureArrayObject($config);
        $config->defaults($this->defaultConfig);
        $config->defaults($this->coreGatewayFactory->createConfig((array) $config));

        $this->populateConfig($config);

        return (array) $config;
    }
{@inheritDoc}