assertEquals(123, newParams.get("key2"));

        // Verify that modifications to new instance don't affect original
        newParams.put("key3", "value3");
        assertTrue(newParams.containsKey("key3"));
        assertFalse(dataStoreParams.containsKey("key3"));

        // Verify that modifications to original don't affect new instance
        dataStoreParams.put("key4", "value4");

    }

    @Override
    protected String getValidationError() {
        return null;
    }

    /**
     * Builds the OpenSearch query for popular words.
     * @return The QueryBuilder instance.
     */
    protected QueryBuilder buildQuery() {
        final BoolQueryBuilder queryBuilder = QueryBuilders.boolQuery();

        if (logger.isInfoEnabled()) {
            logger.info("Load {}", this.getClass().getSimpleName());
        }
        dictionaryManager.addCreator(this);
    }

    /**
     * Creates a new {@link SynonymFile} instance.
     *
     * @param id        The unique identifier for the dictionary file.
     * @param path      The file path of the dictionary.
     * @param timestamp The last modified timestamp of the file.

    }

    /**
     * Builds the query for suggestions.
     * @param q The query string.
     * @param fields The fields to search in.
     * @return The QueryBuilder instance.
     */
    protected QueryBuilder buildQuery(final String q, final List<String> fields) {
        try {
            final QueryBuilder queryBuilder;
            if (Strings.isNullOrEmpty(q)) {

     * If either or both arrays have a length of {@literal 0}, the other array is returned as is.
     * In any case, the returned array is the same instance as the argument array and is not copied.
     * </p>
     *
     * @param <T>
     *            the type of the array elements
     * @param a
     *            first array
     * @param b

   */
  public static Function<Object, String> toStringFunction() {
    return ToStringFunction.INSTANCE;
  }

  // enum singleton pattern
  private enum ToStringFunction implements Function<Object, String> {
    INSTANCE;

    @Override
    public String apply(Object o) {
      checkNotNull(o); // eager for GWT.
      return o.toString();
    }

    @Override

 * The mappings are loaded from configuration and can be dynamically modified
 * at runtime. When a MIME type is not found in the mapping, a default value
 * is returned.
 */
public class FileTypeHelper {
    /** Logger instance for this class */
    private static final Logger logger = LogManager.getLogger(FileTypeHelper.class);

    /** Default file type value returned when MIME type is not found in mappings */

/**
 * A map, each entry of which maps a {@link TypeToken} to an instance of that type. In addition to
 * implementing {@code Map}, the additional type-safe operations {@link #putInstance} and {@link
 * #getInstance} are available.
 *
 * <p>Generally, implementations don't support {@link #put} and {@link #putAll} because there is no
 * way to check an object at runtime to be an instance of a {@link TypeToken}. Instead, caller

/**
 * A map, each entry of which maps a {@link TypeToken} to an instance of that type. In addition to
 * implementing {@code Map}, the additional type-safe operations {@link #putInstance} and {@link
 * #getInstance} are available.
 *
 * <p>Generally, implementations don't support {@link #put} and {@link #putAll} because there is no
 * way to check an object at runtime to be an instance of a {@link TypeToken}. Instead, caller

   * multiple containers in a single method is discouraged in most cases, but it is vital to the
   * iterator tests.
   *
   * @return the new container instance
   * @param newValue the new container instance
   */
  @CanIgnoreReturnValue
  protected C resetContainer(C newValue) {
    container = newValue;
    return container;
  }

  /**
   * @see #expectContents(java.util.Collection)