return fromLongBits(this.value + checkNotNull(val).value);
  }

  /**
   * Returns the result of subtracting this and {@code val}. If the result would have more than 64
   * bits, returns the low 64 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedLong minus(UnsignedLong val) {
    return fromLongBits(this.value - checkNotNull(val).value);
  }

  /**

  public void testCheckNotNull_simple_success() {
    String result = checkNotNull(NON_NULL_STRING);
    assertSame(NON_NULL_STRING, result);
  }

  public void testCheckNotNull_simple_failure() {
    assertThrows(NullPointerException.class, () -> checkNotNull(null));
  }

  public void testCheckNotNull_simpleMessage_success() {
    String result = checkNotNull(NON_NULL_STRING, IGNORE_ME);
    assertSame(NON_NULL_STRING, result);

      contents.add(checkNotNull(element));
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<E> addAll(Iterable<? extends E> elements) {
      super.addAll(elements);
      return this;
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E... elements) {
      checkNotNull(elements); // for GWT
      super.add(elements);

    @Override
    public SortedMap<R, Map<C, V>> headMap(R toKey) {
      checkNotNull(toKey);
      return new StandardRowSortedTable<R, C, V>(sortedBackingMap().headMap(toKey), factory)
          .rowMap();
    }

    @Override
    public SortedMap<R, Map<C, V>> subMap(R fromKey, R toKey) {
      checkNotNull(fromKey);
      checkNotNull(toKey);

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.collect.Synchronized.SynchronizedCollection;
import com.google.common.collect.Synchronized.SynchronizedSet;
import com.google.common.testing.SerializableTester;
import java.io.Serializable;

      this(name, chars, decodabetFor(chars), /* ignoreCase= */ false);
    }

    private Alphabet(String name, char[] chars, byte[] decodabet, boolean ignoreCase) {
      this.name = checkNotNull(name);
      this.chars = checkNotNull(chars);
      try {
        this.bitsPerChar = log2(chars.length, UNNECESSARY);
      } catch (ArithmeticException e) {

        public void put(Range<Comparable<?>> range, Object value) {
          checkNotNull(range);
          throw new IllegalArgumentException(
              "Cannot insert range " + range + " into an empty subRangeMap");
        }

        @Override
        public void putCoalescing(Range<Comparable<?>> range, Object value) {
          checkNotNull(range);
          throw new IllegalArgumentException(

    TypeVariableImpl(D genericDeclaration, String name, Type[] bounds) {
      disallowPrimitiveType(bounds, "bound for type variable");
      this.genericDeclaration = checkNotNull(genericDeclaration);
      this.name = checkNotNull(name);
      this.bounds = ImmutableList.copyOf(bounds);
    }

    public Type[] getBounds() {
      return toArray(bounds);
    }

    public D getGenericDeclaration() {

  static <K, V> CacheLoader<K, V> errorLoader(final Error e) {
    checkNotNull(e);
    return new CacheLoader<K, V>() {
      @Override
      public V load(K key) {
        throw e;
      }
    };
  }

  /** Returns a {@link CacheLoader} that throws the given exception for every request. */
  static <K, V> CacheLoader<K, V> exceptionLoader(final Exception e) {
    checkNotNull(e);
    return new CacheLoader<K, V>() {
      @Override

    final List<F> fromList;
    final Function<? super F, ? extends T> function;

    TransformingSequentialList(List<F> fromList, Function<? super F, ? extends T> function) {
      this.fromList = checkNotNull(fromList);
      this.function = checkNotNull(function);
    }

    /**
     * The default implementation inherited is based on iteration and removal of each element which