/** The key of the configuration. e.g. ___change__me___ */
    String APP_CIPHER_KEY = "app.cipher.key";

    /** The key of the configuration. e.g. sha256 */
    String APP_DIGEST_ALGORITHM = "app.digest.algorithm";

    /** The key of the configuration. e.g. .*password|.*key|.*token|.*secret */
    String APP_ENCRYPT_PROPERTY_PATTERN = "app.encrypt.property.pattern";

// Set configuration key and value using coordination service.
// If coordination service is enabled, the key-value will be stored on the
// leader and become accessible to all workers in the cluster.
// Currently, a config key can only be set with one value, and subsequently
// setting the same key will lead to errors.
//
// Note that the key-values are only expected to be used for cluster

We can do better...

## What makes a dependency { #what-makes-a-dependency }

Up to now you have seen dependencies declared as functions.

But that's not the only way to declare dependencies (although it would probably be the more common).

The key factor is that a dependency should be a "callable".

    return copyToSet(asList(elements));
  }

  // Would use Maps.immutableEntry
  public static <K extends @Nullable Object, V extends @Nullable Object> Entry<K, V> mapEntry(
      K key, V value) {
    return singletonMap(key, value).entrySet().iterator().next();
  }

  private static boolean isEmpty(Iterable<?> iterable) {
    return iterable instanceof Collection
        ? ((Collection<?>) iterable).isEmpty()

    resetContainer(mapEntry(k0(), v0()), mapEntry(k0(), v1()), mapEntry(k1(), v0()));
    Multiset<K> keys = multimap().keys();
    assertEquals(2, keys.count(k0()));
    assertEquals(1, keys.count(k1()));
    assertEquals(3, keys.size());
    assertContainsAllOf(keys, k0(), k1());
    assertContainsAllOf(
        keys.entrySet(), Multisets.immutableEntry(k0(), 2), Multisets.immutableEntry(k1(), 1));
  }

    /** The key of the message: </ul> */
    public static final String ERRORS_FOOTER = "{errors.footer}";

    /** The key of the message: <li><i class="fa fa-exclamation-circle"></i> */
    public static final String ERRORS_PREFIX = "{errors.prefix}";

    /** The key of the message: </li> */
    public static final String ERRORS_SUFFIX = "{errors.suffix}";

    /** The key of the message: {item} must be false. */

    E[] keys = clazz.getEnumConstants();
    int numKeys = keys.length;
    ArrayList<LockGraphNode> nodes = Lists.newArrayListWithCapacity(numKeys);
    // Create a LockGraphNode for each enum value.
    for (E key : keys) {
      LockGraphNode node = new LockGraphNode(getLockName(key));
      nodes.add(node);
      map.put(key, node);
    }

	// preceding the original header. This file contains a set of key-value
	// records, which are used to overcome USTAR's shortcomings, in addition to
	// providing the ability to have sub-second resolution for timestamps.
	//
	// Some newer formats add their own extensions to PAX by defining their
	// own keys and assigning certain semantic meaning to the associated values.

class PacTest {

    private Map<Integer, KerberosKey> keys;

    @BeforeEach
    void setUp() {
        keys = new HashMap<>();
        // Use ARCFOUR-HMAC encryption type (23) which matches KERB_CHECKSUM_HMAC_MD5
        KerberosKey serverKey = new KerberosKey(new KerberosPrincipal("******@****.***"), "serverKey1234567".getBytes(),
                PacSignature.ETYPE_ARCFOUR_HMAC, 1);
        keys.put(PacSignature.ETYPE_ARCFOUR_HMAC, serverKey);
    }

    this.keys = keys;
    this.values = values;
  }

  @Override
  public SampleElements<Entry<K, V>> samples() {
    return SampleElements.mapEntries(keys, values);
  }

  @Override
  public Set<Entry<K, V>> create(Object... elements) {
    Entry<K, V>[] entries = createArray(elements.length);
    arraycopy(elements, 0, entries, 0, elements.length);