// Create the keys from the result.
 private static function CreateResultKeys(LJCDataManager $manager)
 {
   $methodName = "CreateResultKeys";
 
   // See constructor for how to create $manager.
   $rows = $manager->Load();
 
   // Get primary key and unique key.
   $keyNames = [
     "ID",
     "Name",
   ];
   $resultKeys = $manager->CreateResultKeys($rows, $keyNames);
   if (null == $resultKeys
     || 0 == count($resultKeys))
   {
     echo("{$methodName}: \$resultKeys were not created.");
   }
 }