@Override
 public int hashCode() {
   final int prime = 31;
   int result = super.hashCode();
   result = prime * result + ((dataHoraExecucao == null) ? 0 : dataHoraExecucao.hashCode());
   result = prime * result + ((tarefa == null) ? 0 : tarefa.hashCode());
   return result;
 }