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JPX - Java GPX (GPS) Library

There is a newer version: 3.2.0

/*
 * Java GPX Library (jpx-2.0.0).
 * Copyright (c) 2016-2020 Franz Wilhelmstötter
 *
 * 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.
 *
 * Author:
 *    Franz Wilhelmstötter ([email protected])
 */
package io.jenetics.jpx;

import static java.util.Objects.requireNonNull;

import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.Set;

/**
 * Helper methods for handling lists. All method handles null values correctly.
 *
 * @author Franz Wilhelmstötter
 * @version 2.0
 * @since 1.0
 */
final class Lists {

	private Lists() {
	}

	static  List copyOf(final List list) {
		return list == null
			? List.of()
			: List.copyOf(list);
	}

	static  void copyTo(final List source, final List target) {
		requireNonNull(target);
		if (source != null) {
			source.forEach(Objects::requireNonNull);
		}

		target.clear();
		if (source != null) {
			target.addAll(source);
		}
	}

	static int hashCode(final List list) {
		return list != null
			? 17*list.stream().mapToInt(Objects::hashCode).sum() + 31
			: 0;
	}

	static boolean equals(final List b, final List a) {
		boolean result = false;
		if (a != null) {
			if (b != null) {
				result = a.size() == b.size();
				if (result) {
					result = a.isEmpty()|| containsAll(a, b);
				}
			}
		} else {
			result = b == null;
		}

		return result;
	}

	private static boolean containsAll(final Collection a, final Collection b) {
		final Iterator ita = a.iterator();
		final Set