Entry<K, V> entry = iterator.next();
      Entry<K, V> entryCopy = mapEntry(entry.getKey(), entry.getValue());

      iterator.remove();
      assertEquals(initialSize - 1, map.size());

      // Use "entryCopy" instead of "entry" because "entry" might be invalidated after
      // iterator.remove().
      assertFalse(entrySet.contains(entryCopy));
      assertInvariants(map);

        }

        // Simple heuristic based on data entropy
        // In practice, this would be more sophisticated
        int uniqueBytes = countUniqueBytes(data);
        double entropy = (double) uniqueBytes / 256.0;

        // Estimate compression ratio based on entropy
        // Lower entropy = better compression
        return 0.3 + (entropy * 0.6); // Range from 30% to 90%
    }

    @Override

            uniqueCounters.add(bytesToHex(counter));
        }

        // All nonces should be unique (high entropy from SecureRandom)
        assertEquals(sampleSize, uniqueCounters.size(), "All nonces should have unique values");

        // Verify that nonces have good entropy (not predictable)
        // With SecureRandom + counter XOR, they should all be different
        Set<String> uniqueNonces = new HashSet<>();