Yosymfony\Spress\Core\Configuration\Configuration::loadConfiguration PHP Method

    public function loadConfiguration($sitePath, $envName = null)
    {
        if ($this->isSpressSite($sitePath) === false) {
            throw new \RuntimeException(sprintf('Not a Spress site at "%s".', $sitePath));
        }
        $default = $this->loadDefaultConfiguration();
        $dev = $this->loadEnvironmentConfiguration($sitePath, 'dev');
        $result = $this->resolver->resolve(array_merge($default, $dev));
        if (is_null($envName)) {
            $envName = $result['env'];
        }
        if ($envName !== 'dev') {
            $environment = $this->loadEnvironmentConfiguration($sitePath, $envName);
            $environment['env'] = $envName;
            $result = $this->resolver->resolve(array_merge($result, $environment));
        }
        return $result;
    }

 /**
  * @expectedException RuntimeException
  */
 public function testLoadConfigurationEnvironmentEmpty()
 {
     $defaulConfiguration = __DIR__ . '/../../config/default.yml';
     $locator = new FileLocator([]);
     $configLoader = new Config([new YamlLoader($locator)]);
     $config = new Configuration($configLoader, $defaulConfiguration);
     $values = $config->loadConfiguration(__DIR__ . '/../fixtures/project', '');
 }