code: public static long getVisibilityCacheWeight(FluoConfiguration conf) {
      long size = conf.getLong(VISIBILITY_CACHE_WEIGHT, VISIBILITY_CACHE_WEIGHT_DEFAULT);
      if (size <= 0) {
        throw new IllegalArgumentException(
            "Cache size must be positive for " + VISIBILITY_CACHE_WEIGHT);
      }
      return size;
    }
docs: Gets the visibility cache weight
  
  @param conf The FluoConfiguration
  @return The size of the cache value from the property value {@value #VISIBILITY_CACHE_WEIGHT}
  if it is set, else the value of the default value
  {@value #VISIBILITY_CACHE_WEIGHT_DEFAULT}