private function mergeColumnsConfiguration(AutoTablesConfiguration $config, $args)
 {
     $newColArgs = util::array_get($args['columns'], array());
     foreach ($newColArgs as $newColArg) {
         $selector = $newColArg['selector'];
         Ensure::isNotEmpty($selector, 'Missing selector in column configuration');
         $colArg = util::array_get($config->getColumns()[$selector], null);
         if ($colArg) {
             // overwrite the settings
             $config->putColumn($selector, array_merge($colArg, $newColArg));
         } else {
             // define a new entry
             $config->putColumn($selector, $newColArg);
         }
     }
     return $config;
 }