code: public DeploymentCache deployments(long applicationId)
      {
          DeploymentCache cache = deployments.get(applicationId);
          if(cache == null)
              deployments.put(applicationId, cache = new DeploymentCache(applicationId));
          return cache;
      }
docs: Returns the cache of deployments for the given application, creating one if it doesn't exist .
  @param applicationId The id of the application for the cache of deployments
  @return The cache of deployments for the given application