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public class ConectionBD {

  private static UserQueryServiceImpl INSTANCE = null; // Private constructor suppresses

	private ConectionBD() {
	} // creador sincronizado para protegerse de posibles problemas multi-hilo

	// otra prueba para evitar instanciaci�³n m�ºltiple
	private synchronized static void createInstance() {
		if (INSTANCE == null) {
			INSTANCE = new UserQueryServiceImpl();
		}
	}

	public static UserQueryServiceImpl getInstance() {
		if (INSTANCE == null)
			createInstance();
		return INSTANCE;
	}
}