* @since 18.0 (since 3.0 as {@code Objects.firstNonNull()}).
   */
  public static <T> T firstNonNull(@Nullable T first, @Nullable T second) {
    if (first != null) {
      return first;
    }
    if (second != null) {
      return second;
    }
    throw new NullPointerException("Both parameters are null");
  }

  /**
   * Creates an instance of {@link ToStringHelper}.
   *

        TestScriptEngine engine1 = new TestScriptEngine("first");
        TestScriptEngine engine2 = new TestScriptEngine("second");

        scriptEngineFactory.add("test", engine1);
        scriptEngineFactory.add("test", engine2);

        // Should get the second engine
        ScriptEngine retrieved = scriptEngineFactory.getScriptEngine("test");
        assertEquals(engine2, retrieved);
    }

        Instant first = MonotonicClock.now();
        Thread.sleep(10); // Small delay
        Instant second = MonotonicClock.now();
        Thread.sleep(10); // Small delay
        Instant third = MonotonicClock.now();

        assertTrue(first.isBefore(second), "Time should progress forward between measurements");
        assertTrue(second.isBefore(third), "Time should progress forward between measurements");
    }

    @Test

        byte[] first = impl.getBuffer(); // should return slot 0 -> a
        byte[] second = impl.getBuffer(); // then slot 1 -> c
        byte[] third = impl.getBuffer(); // cache empty -> new with size 3

        assertSame(a, first, "First get should return first cached buffer");
        assertSame(c, second, "Second get should return second cached buffer");

	driveCountMD = NewGaugeMD(driveCount,
		"Count of all drives")

	// iostat related
	driveReadsPerSecMD = NewGaugeMD(driveReadsPerSec,
		"Reads per second on a drive",
		allDriveLabels...)
	driveReadsKBPerSecMD = NewGaugeMD(driveReadsKBPerSec,
		"Kilobytes read per second on a drive",
		allDriveLabels...)
	driveReadsAwaitMD = NewGaugeMD(driveReadsAwait,
		"Average time for read requests served on a drive",
		allDriveLabels...)

   * @since 18.0 (since 3.0 as {@code Objects.firstNonNull()}).
   */
  public static <T> T firstNonNull(@Nullable T first, @Nullable T second) {
    if (first != null) {
      return first;
    }
    if (second != null) {
      return second;
    }
    throw new NullPointerException("Both parameters are null");
  }

  /**
   * Creates an instance of {@link ToStringHelper}.
   *

```Python
old_dict = {
    "old key": "old value",
    "second old key": "second old value",
}
new_dict = {**old_dict, "new key": "new value"}
```

📥, `new_dict` 🔜 🔌 🌐 🔑-💲 👫 ⚪️➡️ `old_dict` ➕ 🆕 🔑-💲 👫:

```Python
{
    "old key": "old value",
    "second old key": "second old value",
    "new key": "new value",
}
```

        scriptExecutor.addShutdownListener(listener1);

        // Add second listener (should replace first)
        TestShutdownListener listener2 = new TestShutdownListener();
        scriptExecutor.addShutdownListener(listener2);

        // Call shutdown
        scriptExecutor.shutdown();

        // Verify only second listener was called
        assertFalse(listener1.wasShutdownCalled());

        // Note: Real SmbTransportImpl will report as disconnected without actual socket
        SmbTransportImpl second = testPool.getSmbTransport(ctx, address, 445, false);

        // Then: Will create new connection since real transport has no socket
        assertNotSame(first, second, "Should create new connection when first is disconnected");
    }

    @Test

        SmbTreeHandleImpl tree = fh.getTree();
        // do not actually perform network call
        when(tree.send(any(jcifs.internal.Request.class), any(RequestParam.class))).thenReturn(null);

        raf.setLength(100L);

        verify(tree, times(1)).send(any(Smb2SetInfoRequest.class), eq(RequestParam.NO_RETRY));
    }

    @Test