public function getEnviosFor($esc_id)
 {
     $sql = "select * from documento_destinatario where dod_destinatario = {$esc_id};";
     $result = $this->retrieve($sql);
     $retorno = [];
     while ($qr = mysqli_fetch_assoc($result)) {
         $dod = new DocumentoDestinatario();
         $dod->setDod_id($qr["dod_id"]);
         $dod->setDod_envio($qr["dod_envio"]);
         $dod->setDod_destinatario($qr["dod_destinatario"]);
         $dod->setDod_visto($qr["dod_visto"]);
         array_push($retorno, $dod);
     }
     return $retorno;
 }