}

    // Helper method to assert array equality
    private void assertArrayEquals(String[] expected, String[] actual) {
        if (expected == null && actual == null) {
            return;
        }
        assertNotNull("Expected array is null but actual is not", expected);
        assertNotNull("Actual array is null but expected is not", actual);
        assertEquals("Array lengths differ", expected.length, actual.length);

        assertNotNull(buffer, "getBuffer should never return null");
        assertSame(expectedBuffer, buffer, "Should return configured buffer");
    }

    @Test
    @DisplayName("releaseBuffer should accept byte arrays gracefully")
    void testReleaseBufferContract() {
        // Given
        byte[] buffer = new byte[1024];
        doNothing().when(mockBufferCache).releaseBuffer(buffer);

        // When & Then

      throw new ArrayIndexOutOfBoundsException("Required array size too large: " + longSize);
    }

    char[] array = new char[size];
    string.getChars(0, len, array, 0);
    int n;
    for (n = len; n < size - n; n <<= 1) {
      System.arraycopy(array, 0, array, n, n);
    }
    System.arraycopy(array, 0, array, n, size - n);
    return new String(array);
  }

  /**

   */
  public abstract long padToLong();

  /**
   * Returns the value of this hash code as a byte array. The caller may modify the byte array;
   * changes to it will <i>not</i> be reflected in this {@code HashCode} object or any other arrays
   * returned by this method.
   */
  // TODO(user): consider ByteString here, when that is available
  public abstract byte[] asBytes();

  /**

import static org.junit.jupiter.api.Assertions.assertNotSame;
import static org.junit.jupiter.api.Assertions.assertThrows;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

import org.junit.jupiter.api.Test;

class HMACT64Test {

    private static final byte[] TEST_KEY = "testkey".getBytes();
    private static final byte[] LONG_TEST_KEY = new byte[80]; // Longer than 64 bytes

            writeBytes.setAccessible(true);
            writeBytes.invoke(cancel, dst, 0);

            // Then - array should remain unchanged
            assertArrayEquals(originalDst, dst);
        }

        @Test
        @DisplayName("Read operations should not modify buffer array")
        void testReadOperationsDoNotModifyArray() throws Exception {
            // Given

     */
    public void setNonce(final byte[] nonce) {
        if (nonce.length == 12) {
            // For CCM cipher, pad nonce to 16 bytes with zeros
            java.util.Arrays.fill(this.nonce, (byte) 0);
            System.arraycopy(nonce, 0, this.nonce, 0, 12);
        } else if (nonce.length == 16) {
            // For GCM cipher, use full 16-byte nonce

           */
          toJoin = Arrays.copyOf(toJoin, expandedCapacity(toJoin.length, toJoin.length + 1));
        }
        toJoin[i++] = toString(part);
      }
      // We might not have seen the expected number of elements, as discussed above.
      if (i != toJoin.length) {
        toJoin = Arrays.copyOf(toJoin, i);
      }
      return String.join(separator, toJoin);
    }

      if (object instanceof ConcatenatedHashFunction) {
        ConcatenatedHashFunction other = (ConcatenatedHashFunction) object;
        return Arrays.equals(functions, other.functions);
      }
      return false;
    }

    @Override
    public int hashCode() {
      return Arrays.hashCode(functions);
    }
  }

  /**
   * Linear CongruentialGenerator to use for consistent hashing. See

//  num_opers - `num_opers` contains the number of elements in the `opers` array
//              or a special value of -1 meaning that no array is given.
//              The distinction between an empty array of operations and no
//              array of operations is necessary to distinguish the case of
//              creating a function with no body (e.g. identity or permutation)