throw new UnsupportedOperationException();
  }

  private <T> T pickInstance(T[] instances, T defaultValue) {
    return pickInstance(Arrays.asList(instances), defaultValue);
  }

  private <T> T pickInstance(Collection<T> instances, T defaultValue) {
    if (instances.isEmpty()) {
      return defaultValue;
    }
    // generateInt() is 1-based.

		AuditKafka:   make(map[string]kafka.Config),
	}

	return cfg
}

func getCfgVal(envName, key, defaultValue string) string {
	if key != config.Default {
		envName = envName + config.Default + key
	}
	return env.Get(envName, defaultValue)
}

func lookupLegacyConfigForSubSys(ctx context.Context, subSys string) Config {
	cfg := NewConfig()
	switch subSys {

    @Override
    public Object get(final Object key) {
        return getProperties().get(key);
    }

    @Override
    public String getProperty(final String key, final String defaultValue) {
        return getProperties().getProperty(key, defaultValue);
    }

    @Override
    public String getProperty(final String key) {
        return getProperties().getProperty(key);
    }

    @Override

  )
  fun handshake(): Handshake? = handshake

  fun headers(name: String): List<String> = headers.values(name)

  @JvmOverloads
  fun header(
    name: String,
    defaultValue: String? = null,
  ): String? = headers[name] ?: defaultValue

  @JvmName("-deprecated_headers")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "headers"),
    level = DeprecationLevel.ERROR,
  )

  }

  @Override
  public final @Nullable V getOrDefault(@Nullable Object key, @Nullable V defaultValue) {
    V result = get(key);
    // TODO(b/192579700): Use a ternary once it no longer confuses our nullness checker.
    if (result != null) {
      return result;
    } else {
      return defaultValue;
    }
  }

  private transient @Nullable ImmutableSet<Entry<K, V>> cachedEntrySet = null;

    // We assume that all defaults are generics-safe, even if they aren't,
    // we take the risk.
    @SuppressWarnings("unchecked")
    T defaultValue = (T) defaults.getInstance(type.getRawType());
    if (defaultValue != null) {
      return defaultValue;
    }
    @SuppressWarnings("unchecked") // All arbitrary instances are generics-safe
    T arbitrary = (T) ArbitraryInstances.get(type.getRawType());

    /*
     * Even though it's weird to pass a defaultValue that is null, some callers do so. Those who
     * pass a literal "null" should probably just use `get`, but I would expect other callers to
     * pass an expression that *might* be null. This could happen with:
     *
     * - a `getFooOrDefault(@Nullable Foo defaultValue)` method that returns

     *
     * @param key the property key.
     * @param defaultValue a default value.
     * @return The property value of the default value
     */
    public String getProperty(String key, String defaultValue) {
        if (this.get(key) != null) {
            return this.get(key);
        }
        return defaultValue;
    }

    @Override
    public Set<Entry<String, String>> entrySet() {

     *
     * @param key the property key.
     * @param defaultValue a default value.
     * @return The property value of the default value
     */
    public String getProperty(String key, String defaultValue) {
        if (this.get(key) != null) {
            return this.get(key);
        }
        return defaultValue;
    }

    @Override
    public Set<Entry<String, String>> entrySet() {

        properties.load(new StringReader(TEST_PROPERTIES));

        String test = properties.getProperty("test");
        assertEquals("test", test);

        String defaultValue = properties.getProperty("notfound", "default");
        assertEquals("default", defaultValue);

        properties.setProperty("another", "another");
        Object o1 = properties.getProperty("another");
        assertEquals("another", o1);