/**
 * An extension of {@code DataInput} for reading from in-memory byte arrays; its methods offer
 * identical functionality but do not throw {@link IOException}.
 *
 * <p><b>Warning:</b> The caller is responsible for not attempting to read past the end of the
 * array. If any method encounters the end of the array prematurely, it throws {@link

 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Callables {
  private Callables() {}

  /** Creates a {@code Callable} which immediately returns a preset value each time it is called. */
  public static <T extends @Nullable Object> Callable<T> returning(@ParametricNullness T value) {
    return () -> value;
  }

  /**
   * Creates an {@link AsyncCallable} from a {@link Callable}.
   *

```

### About `__name__ == "__main__"`

The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:

<div class="termy">

```console
$ python myapp.py
```

</div>

but is not called when another file imports it, like in:

```Python
from myapp import app
```

#### More details

Let's say your file is named `myapp.py`.

        SmbInfoAllocation info = new SmbInfoAllocation();
        
        // Read total allocation units.
        info.alloc = readInt8( buffer, bufferIndex );
        bufferIndex += 8;
        
        // read caller available allocation units 
        info.free = readInt8( buffer, bufferIndex );
        bufferIndex += 8;

        // skip actual free units
        bufferIndex += 8;
        

    // 3 options here for ordering
    // 1) Legacy Platform - based on the Platform/Provider existing ordering in
    // sslSocket.enabledCipherSuites
    // 2) OkHttp Client - based on MODERN_TLS source code ordering
    // 3) Caller specified but assuming the visible defaults in MODERN_CIPHER_SUITES are rejigged
    // to match legacy i.e. the platform/provider
    //
    // Opting for 2 here and keeping MODERN_TLS in line with secure browsers.

	}

	if cap(b) != bp.wcap {
		// someone tried to put back buffer which is not part of this buffer pool
		// we simply don't put this back into pool, a modified buffer provided
		// by this package is no more usable, callers make sure to not modify
		// the capacity of the buffer.
		return
	}

	select {
	case bp.c <- b[:bp.w]:
		// buffer went back into pool
	default:
		// buffer didn't go back into pool, just discard
	}
}

     * caught above) can linger and affect listeners.
     */
  }

  /**
   * Called before runInterruptibly - if true, runInterruptibly and afterRanInterruptibly will not
   * be called.
   */
  abstract boolean isDone();

  /**
   * Do interruptible work here - do not complete Futures here, as their listeners could be
   * interrupted.

For example, you could create a project called `philosophers-stone`, this program depends on another package called **`harry`, using the version `1`**. So, you need to install `harry`.

```mermaid
flowchart LR
    stone(philosophers-stone) -->|requires| harry-1[harry v1]
```

    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Finish the task by unblocking the task latch.  Then wait for the
    // listener to be called by blocking on the listener latch.
    taskLatch.countDown();
    assertEquals(25, task.get().intValue());
    assertTrue(listenerLatch.await(5, SECONDS));
    assertTrue(task.isDone());

    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Finish the task by unblocking the task latch.  Then wait for the
    // listener to be called by blocking on the listener latch.
    taskLatch.countDown();
    assertEquals(25, task.get().intValue());
    assertTrue(listenerLatch.await(5, SECONDS));
    assertTrue(task.isDone());