List<Artifact> list = new ArrayList<>();
        list.add(newArtifact("b"));
        list.add(newArtifact("a"));
        list.add(newArtifact("c"));
        list.add(newArtifact("e"));
        list.add(newArtifact("d"));

        Map<String, Artifact> map = ArtifactUtils.artifactMapByVersionlessId(list);
        assertNotNull(map);
        assertEquals(list, new ArrayList<>(map.values()));
    }

      public void perform(List<Integer> list) {
        list.remove(0);
      }
    };
  }

  static ListFrobber nop() {
    return new ListFrobber() {
      @Override
      public void perform(List<Integer> list) {}
    };
  }

  /** A list that mutates itself after every call to each of its {@link List} methods. */
  interface ConcurrentlyMutatedList<E> extends List<E> {
    /**

    }

    /**
     * Retrieves a list of URLs that are in the user's favorites from the provided URL list.
     * This method filters the input URL list to return only those URLs that the specified user
     * has marked as favorites.
     *
     * @param userCode the unique code identifying the user
     * @param urlList the list of URLs to check against the user's favorites

   * Multimap} interface.
   */
  @Override
  public List<V> get(@ParametricNullness K key) {
    return (List<V>) super.get(key);
  }

  /**
   * {@inheritDoc}
   *
   * <p>Because the values for a given key may have duplicates and follow the insertion ordering,

    @Override
    protected List<String> create(String[] elements) {
      return ImmutableList.<String>builder().addAll(asList(elements)).build();
    }
  }

  public static class BuilderReversedListGenerator extends TestStringListGenerator {
    @Override
    protected List<String> create(String[] elements) {
      List<String> list = asList(elements);
      Collections.reverse(list);

        }
        set.clear();
    }

    private void assertFieldLogs(Map<String, List<String>> fieldLogMap) {
        @SuppressWarnings("unchecked")
        Map<String, List<String>> map = (Map<String, List<String>>) getMockRequest().getAttribute(Constants.FIELD_LOGS);
        if (fieldLogMap != null) {
            assertEquals(fieldLogMap, map);
        }

        return doBatchInsert(new BulkList<>(list, call, entityCall), null);
    }

    public int[] batchUpdate(List<User> list) {
        return batchUpdate(list, null, null);
    }

    public int[] batchUpdate(List<User> list, RequestOptionCall<BulkRequestBuilder> call) {
        return batchUpdate(list, call, null);
    }

    public int[] batchUpdate(List<User> list, RequestOptionCall<BulkRequestBuilder> call,

        assertEquals(2, notifications.size());

        // Modify input list - should not affect returned list
        inputList.clear();
        assertEquals(2, notifications.size());

        // Try to modify returned list - behavior depends on implementation
        // This tests that the implementation properly handles list modifications
        try {
            notifications.clear();

                assertEquals(pageSize, list.size());
                assertEquals(allRecordCount, list.getAllRecordCount());
                assertEquals(100, list.getAllPageCount());
                assertEquals(20, list.getCurrentEndRecordNumber());
                assertEquals(2, list.getCurrentPageNumber());
                assertEquals(11, list.getCurrentStartRecordNumber());
                assertEquals(0, list.getOffset());

        if (list.contains(key)) {
          assertEquals(list.lastIndexOf(key), answer);
          return;
        }
        break;
      case ANY_PRESENT:
        if (list.contains(key)) {
          assertEquals(key, list.get(answer));
          return;
        }
        break;
      case FIRST_AFTER:
        if (list.contains(key)) {
          assertEquals(list.lastIndexOf(key) + 1, answer);
          return;
        }