* @throws NullPointerException if both {@code first} and {@code second} are null
   * @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");
  }

  /**

        if (isEmpty(s1)) {
            return false;
        }
        return s1.indexOf(s2) >= 0;
    }

    /**
     * Returns whether two strings are equal. If both are null, returns <code>true</code>.
     *
     * @param target1
     *            the first string
     * @param target2
     *            the second string

Некоторые возможные идеи:

* «Init Container» в Kubernetes, который запускается перед контейнером с приложением
* Bash‑скрипт, который выполняет предварительные шаги, а затем запускает приложение
    * При этом всё равно нужен способ запускать/перезапускать *этот* bash‑скрипт, обнаруживать ошибки и т.п.

/// tip | Совет

        // Get another region - should potentially reuse from pool
        RdmaMemoryRegion region2 = bufferManager.getSendRegion(1024);
        assertNotNull(region2);

        // Both regions should be valid
        assertTrue(region1.isValid() || !region1.isValid()); // Either state is OK after release
        assertTrue(region2.isValid(), "New region should be valid");
    }

    // GET /api/admin/duplicatehost/settings
    // PUT /api/admin/duplicatehost/settings
    /**
     * Returns list of duplicate host settings.
     * Supports both GET and PUT requests for retrieving paginated duplicate host configurations.
     *
     * @param body search parameters for filtering and pagination

* for **output** it will be **required** (and possibly `None`, or in JSON terms, `null`)

### Model for Output in Docs { #model-for-output-in-docs }

You can check the output model in the docs too, **both** `name` and `description` are marked as **required** with a **red asterisk**:

<div class="screenshot">
<img src="/img/tutorial/separate-openapi-schemas/image03.png">
</div>

import java.util.EnumMap;
import java.util.Map;

/**
 * A {@code BiMap} backed by two {@code EnumMap} instances. Null keys and values are not permitted.
 * An {@code EnumBiMap} and its inverse are both serializable.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#bimap">{@code BiMap}</a>.
 *
 * @author Mike Bostock
 * @since 2.0
 */

        for (int i = 0; i < elements.length; i++) {
          String element = elements[i];
          if (multiset1.contains(element) || multiset2.contains(element)) {
            // add to both; the one already containing it will have more
            multiset1.add(element);
            multiset2.add(element);
          } else if (i % 2 == 0) {
            multiset1.add(elements[i]);
          } else {

	checksumCombined = append(checksumCombined, part2Checksum.Raw...)
	checksumCombined = append(checksumCombined, part3Checksum.Raw...)

	// Create the final checksum (checksum of the combined checksums)
	// Add BOTH the multipart flag AND the includes-multipart flag
	finalChecksumType := checksumType | ChecksumMultipart | ChecksumIncludesMultipart
	finalChecksum := NewChecksumFromData(finalChecksumType, checksumCombined)

////

//// tab | Info

... However, quotes inside code snippets must stay as is.

////

## code blocks { #code-blocks }

//// tab | Test

A Bash code example...

```bash
# Print a greeting to the universe
echo "Hello universe"
```

...and a console code example...

```console