import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.Predicate;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link Collection} whose contents will never change, and which offers a few additional

 *   <li>Use of {@link java.util.Objects#requireNonNull(Object)} is generally discouraged, since
 *       {@link #verifyNotNull(Object)} and {@link Preconditions#checkNotNull(Object)} perform the
 *       same function with more clarity.
 * </ul>
 *
 * <h3>Warning about performance</h3>
 *
 * <p>Remember that parameter values for message construction must all be computed eagerly, and

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      Work (including but not limited to damages for loss of goodwill,
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      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.

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      Work (including but not limited to damages for loss of goodwill,
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      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.

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      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all
      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.

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