String[] inputs = { "input" };
        CharMappingItem item = new CharMappingItem(1L, inputs, "line1\nline2");

        assertEquals("line1 line2", item.getOutput());
    }

    public void test_constructor_withNullOutput() {
        // Test with null output
        String[] inputs = { "input" };
        CharMappingItem item = new CharMappingItem(1L, inputs, null);

        assertNull(item.getOutput());

      Iterable<? extends T>... inputs) {
    return concatNoDefensiveCopy(Arrays.copyOf(inputs, inputs.length));
  }

  /**
   * Returns a fluent iterable that combines several iterables. The returned iterable has an
   * iterator that traverses the elements of each iterable in {@code inputs}. The input iterators
   * are not polled until necessary.
   *

      Iterable<? extends T>... inputs) {
    return concatNoDefensiveCopy(Arrays.copyOf(inputs, inputs.length));
  }

  /**
   * Returns a fluent iterable that combines several iterables. The returned iterable has an
   * iterator that traverses the elements of each iterable in {@code inputs}. The input iterators
   * are not polled until necessary.
   *

        item.setNewInput("");
        assertEquals("StopwordsItem [id=123, inputs=word, newInputs=]", item.toString());
    }

    public void test_toLineString() {
        // Test toLineString method
        StopwordsItem item = new StopwordsItem(1, "original");
        assertEquals("original", item.toLineString());

        // When updated, should return newInput

   * identical inputs: This sounds like it ought to be a problem here, since the goals of this class
   * include testing that {@code equals()} is reflexive and is tolerant of {@code null}. However,
   * there's no problem. The reason: {@link EqualsTester} tests {@code null} and identical inputs
   * directly against {@code equals()} rather than through the {@code Equivalence}.
   */

        // Same object
        assertTrue(item1.equals(item1));

        // Same input, different id
        assertTrue(item1.equals(item2));

        // Different input
        assertFalse(item1.equals(item3));

        // Same id and input
        assertTrue(item1.equals(item4));

        // Null object
        assertFalse(item1.equals(null));

  @SafeVarargs
  public static <T extends @Nullable Object> Iterable<T> concat(Iterable<? extends T>... inputs) {
    return FluentIterable.concat(inputs);
  }

  /**
   * Combines multiple iterables into a single iterable. The returned iterable has an iterator that
   * traverses the elements of each iterable in {@code inputs}. The input iterators are not polled
   * until necessary.
   *

            final VaErrorHook hook) {
        return getEntity(form).map(entity -> {
            final String[] newInputs = splitLine(form.inputs);
            validateMappingString(action, newInputs, "inputs", hook);
            entity.setNewInputs(newInputs);
            final String newOutput = form.output;
            entity.setNewOutput(newOutput);
            return entity;
        });

        @Override
        public String getName() {
            return "TestGenerator";
        }

        @Override
        public boolean generate(String thumbnailId, File outputFile) {
            // Validate inputs
            if (thumbnailId == null || thumbnailId.isEmpty() || outputFile == null) {
                return false;
            }

            // Check if parent directory is writable

    return concatNoDefensiveCopy(Arrays.copyOf(inputs, inputs.length));
  }

  /**
   * Combines multiple iterators into a single iterator. The returned iterator iterates across the
   * elements of each iterator in {@code inputs}. The input iterators are not polled until
   * necessary.
   *