content: /*
   * Copyright © 2018-2025 Commonwealth Scientific and Industrial Research
   * Organisation (CSIRO) ABN 41 687 119 230.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package au.csiro.pathling.utilities;
  
  import jakarta.annotation.Nonnull;
  import java.util.List;
  import java.util.Optional;
  
  /**
   * Utility class containing some List helper functions.
   *
   * @author Piotr Szul
   */
  public abstract class Lists {
  
    private Lists() {
    }
  
    /**
     * Returns an optional of given list for non-empty list, or empty optional otherwise.
     *
     * @param list list to convert
     * @param <T> type of list elements
     * @return option of given list for non-empty list, or empty option otherwise
     */
    @Nonnull
    public static <T> Optional<List<T>> optionalOf(@Nonnull final List<T> list) {
      return list.isEmpty()
             ? Optional.empty()
             : Optional.of(list);
    }
  }
  