/**
  * static function that change the first argument identical to the second
  *
  * @param Client $client        	
  * @return void
  */
 private static function updateState(Client $client1, Client $client2)
 {
     // $flag = false;
     foreach ($client1->getProprities() as $key => $value) {
         if ($value != $client2->getProprities()[$key]) {
             $value = $client2->getProprities()[$key];
         }
     }
     // return flag;
     // $client1->setName ( $client2->getName () );
     // $client1->setAge ( $client2->getAge () );
     // $client1->setEmail ( $client2->getEmail () );
     // $client1->setLevel ( $client2->getLevel () );
     // $client1->setPassword ( $client2->getPassword () );
 }