docs: protected void ensureDeviceCacheHolder(Integer deviceId, AllocationShape shape) {
          if (!deviceCache.containsKey(deviceId)) {
              try {
                  synchronized (this) {
                     if (!deviceCache.containsKey(deviceId)) {
                          deviceCache.put(deviceId, new ConcurrentHashMap<AllocationShape, CacheHolder>());
                      }
                  }
              } catch (Exception e) {
                  throw new RuntimeException(e);
              }
          }
  
          if (!deviceCache.get(deviceId).containsKey(shape)) {
              try {
                  singleLock.acquire();
  
                  if (!deviceCache.get(deviceId).containsKey(shape)) {
                      deviceCache.get(deviceId).put(shape, new CacheHolder(shape, deviceCachedAmount.get(deviceId)));
                  }
              } catch (Exception e) {
  
              } finally {
                  singleLock.release();
              }
          }
      }