Getting Build from QueueReference

Hi All¡
First of all sorru for my ignorance, I´m new dealing with jenkins-api. I´m going to explain my doubt:

I have a process that call jenkins in order to launch a build:

` JenkinsServer jenkins = new JenkinsServer(new URI(
"https://jenkins"), "xxxxx",
"xxxxx");
Map params = new HashedMap();
params.put("svnPath","xxxxxx@44117");

QueueReference queue = jenkins.getJob("JARGENERATION").build(params);`

Now I´ve to fetch the artifact and I´m trying to get it by:

`QueueItem item = jenkins.getQueueItem(queue);
BuildWithDetails build = jenkins.getBuild(item).details();`

I guest that the problem is that the build is in process, but by debugging always get NullPointer inside the API.

Some workround of how to fetch the artifact from a build recently launched?

Thanks in advance

Lea los puntos de entrada JenkinsServer.getQueueItem(queue), QueueItem y getBuild(item) mencionados en el informe. Reproduzca la NullPointerException mientras el build en cola todavía se está ejecutando y después de que finalice. Se considera terminado cuando el cliente proporciona una forma documentada y fiable de obtener el build completado y su artefacto, o informa claramente de por qué no puede hacerlo.

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