code: private static boolean isHashConfigurationIsSupported(long numBuckets, int tagBits, int hashSize) {
  		int hashBitsNeeded = getTotalBitsNeeded(numBuckets, tagBits);
  		switch (hashSize) {
  		case 32:
  		case 64:
  			return hashBitsNeeded <= hashSize;
  		default:
  		}
  		if (hashSize >= 128)
  			return tagBits <= 64 && getIndexBitsUsed(numBuckets) <= 64;
  		return false;
  	}
docs: Determines if the chosen hash function is long enough for the table
  configuration used.