code: public InstallationJob getJob(Plugin plugin) {
          List<UpdateCenterJob> jobList = getJobs();
          Collections.reverse(jobList);
          for (UpdateCenterJob job : jobList)
              if (job instanceof InstallationJob) {
                  InstallationJob ij = (InstallationJob)job;
                  if (ij.plugin.name.equals(plugin.name) && ij.plugin.sourceId.equals(plugin.sourceId))
                      return ij;
              }
          return null;
      }
docs: Returns latest install/upgrade job for the given plugin.
  @return InstallationJob or null if not found