|   plugins should document which type you must use.
   |
   | * provides: A list of key/value-pairs.
   |   Based on the toolchain-configuration in the pom.xml Maven will search for
   |   matching <provides/> configuration. You can decide for yourself which key-value
   |   pairs to use. Often used keys are 'version', 'vendor' and 'arch'. By default
   |   the version has a special meaning. If you configured in the pom.xml '1.5'

    }

    /**
     * Retrieves an extractor for the specified key.
     * If multiple extractors are associated with the key, returns a composite extractor
     * that tries each extractor in order until one succeeds.
     *
     * @param key the key to look up
     * @return the extractor for the key, or null if not found
     */
    public Extractor getExtractor(final String key) {

              }

              @Override
              public @Nullable String put(String key, String value) {
                checkNotNull(key);
                return map.put(key, value);
              }
            };
          }
        },
        "HashMap w/out null keys",
        ALLOWS_NULL_VALUES);
  }

  private static Test testsForHashMapNullValuesForbidden() {

/**
 * {@code ObjectCountLinkedHashMap} is a subclass of {@code ObjectCountHashMap} with insertion
 * iteration order, and uses arrays to store key objects and count values. Comparing to using a
 * traditional {@code LinkedHashMap} implementation which stores keys and count values as map
 * entries, {@code ObjectCountLinkedHashMap} minimizes object allocation and reduces memory
 * footprint.
 */
@GwtCompatible
@NullMarked

  // For each cell in iteration order, the index of that cell's row key in the row key list.
  @SuppressWarnings("Immutable") // We don't modify this after construction.
  private final int[] cellRowIndices;

  // For each cell in iteration order, the index of that cell's column key in the list of column
  // keys present in that row.
  @SuppressWarnings("Immutable") // We don't modify this after construction.

		t.Skip("skip sqlite, sqlserver due to it doesn't support multiple primary keys with auto increment")
	}

	if name := DB.Dialector.Name(); name == "postgres" {
		t.Skip("skip postgres due to it only allow unique constraint matching given keys")
	}
	if name := DB.Dialector.Name(); name == "gaussdb" {
		t.Skip("skip gaussdb due to it only allow unique constraint matching given keys")
	}

#### 3.2.1 Generate a private key with ECDSA

Use the following command to generate a private key with ECDSA:

```sh
openssl ecparam -genkey -name prime256v1 | openssl ec -out private.key
```

A response similar to this one should be displayed:

```
read EC key
writing EC key
```

Alternatively, use the following command to generate a private ECDSA key protected by a password:

```sh

    builder.put("key", "value");
    assertThat(builder.build().entries()).containsExactly(Maps.immutableEntry("key", "value"));
  }

  public void testBuilderWithExpectedKeysPositive() {
    ImmutableListMultimap.Builder<String, String> builder =
        ImmutableListMultimap.builderWithExpectedKeys(1);
    builder.put("key", "value");

  public @Nullable V forcePut(K key, @ParametricNullness V value) {
    return super.forcePut(key, value);
  }

  /** Returns the associated key type. */
  @GwtIncompatible
  public Class<K> keyType() {
    return keyTypeOrObjectUnderJ2cl;
  }

  /**
   * @serialData the key class, number of entries, first key, first value, second key, second value,
   *     and so on.
   */

		if now.After(ent.ExpiresAt) {
			continue
		}
		maps[ent.Key] = ent.Value
		// keys = append(keys, ent.Key)
	}
	return maps
}

// Keys returns a slice of the keys in the cache, from oldest to newest.
// Expired entries are filtered out.
func (c *LRU[K, V]) Keys() []K {
	c.mu.Lock()
	defer c.mu.Unlock()
	keys := make([]K, 0, len(c.items))
	now := time.Now()