// Decrypt
        char[] decrypted = storage.decryptCredentials(encrypted);
        assertNotNull(decrypted, "Decrypted data should not be null");
        assertArrayEquals(plaintext, decrypted, "Decrypted should match original");

        // Clean up sensitive data
        Arrays.fill(plaintext, '\0');
        Arrays.fill(decrypted, '\0');
    }

    @Test
    public void testEncryptDecryptEmpty() throws Exception {

/*
 * Copyright 2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions

      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions

      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions

    assertSideEffectFree(hash);
    assertReadableBytes(hash);
  }

  private static void assertSideEffectFree(HashCode hash) {
    byte[] original = hash.asBytes();
    byte[] mutated = hash.asBytes();
    mutated[0]++;
    assertTrue(Arrays.equals(original, hash.asBytes()));
  }

  private static void assertReadableBytes(HashCode hashCode) {
    assertTrue(hashCode.bits() >= 32); // sanity

/*
 * Copyright 2019 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2021 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2019 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

  public final String[] createKeyArray(int length) {
    return new String[length];
  }

  @Override
  public final String[] createValueArray(int length) {
    return new String[length];
  }

  /** Returns the original element list, unchanged. */
  @Override
  public Iterable<Entry<String, String>> order(List<Entry<String, String>> insertionOrder) {
    return insertionOrder;
  }