code: public Builder<T> useReferenceInRam(
          int maxRamSizeBytes, SizeOf<T> handlerSizeOf
      ) {
          this.ramMode = DualCacheRamMode.ENABLE_WITH_REFERENCE;
          this.maxRamSizeBytes = maxRamSizeBytes;
          this.sizeOf = handlerSizeOf;
          return this;
      }
docs: Store directly objects in ram (without serialization/deserialization).
  You have to provide a way to compute the size of an object in
  ram to be able to used the LRU capacity of the ram cache.
  
  @param maxRamSizeBytes is the max amount of ram which can be used by the ram cache.
  @param handlerSizeOf   computes the size of object stored in ram.
  @return the builder.