import com.google.common.annotations.GwtCompatible;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/**
 * Provides static methods for working with {@link Comparator} instances. For many other helpful
 * comparator utilities, see either {@code Comparator} itself (for Java 8+), or {@code

import java.io.Closeable;
import java.io.EOFException;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.nio.CharBuffer;
import java.util.ArrayList;
import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * Provides utility methods for working with character streams.
 *
 * @author Chris Nokleberg
 * @author Bin Zhu
 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible

import com.google.common.annotations.VisibleForTesting;
import com.google.errorprone.annotations.InlineMe;
import com.google.errorprone.annotations.InlineMeValidationDisabled;
import java.util.logging.Logger;
import org.jspecify.annotations.Nullable;

/**
 * Static utility methods pertaining to {@code String} or {@code CharSequence} instances.
 *
 * @author Kevin Bourrillion
 * @since 3.0
 */
@GwtCompatible

import java.lang.ref.WeakReference;
import java.util.ConcurrentModificationException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.jspecify.annotations.Nullable;

/**
 * A builder of {@link ConcurrentMap} instances that can have keys or values automatically wrapped
 * in {@linkplain WeakReference weak} references.
 *
 * <p>Usage example:
 *

import com.google.common.testing.EqualsTester;
import com.google.common.testing.SerializableTester;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link PairedStats}. This tests instances created by {@link
 * PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
@J2ktIncompatible

import com.google.common.collect.UnmodifiableIterator;
import com.google.common.math.IntMath;
import com.google.common.primitives.Ints;
import java.util.AbstractSet;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * This class provides a skeletal implementation of {@link BaseGraph}.
 *
 * <p>The methods implemented in this class should not be overridden unless the subclass admits a

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * CompactLinkedHashSet is an implementation of a Set, which a predictable iteration order that
 * matches the insertion order. All optional operations (adding and removing) are supported. All

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.concurrent.LazyInit;
import java.io.Serializable;
import java.util.Comparator;
import java.util.Objects;
import org.jspecify.annotations.Nullable;

/**
 * A generalized interval on any ordering, for internal use. Supports {@code null}. Unlike {@link
 * Range}, this allows the use of an arbitrary comparator. This is designed for use in the

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

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.math.BigInteger;
import org.jspecify.annotations.Nullable;

/**
 * A wrapper class for unsigned {@code long} values, supporting arithmetic operations.
 *
 * <p>In some cases, when speed is more important than code readability, it may be faster simply to

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.testing.NullPointerTester;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;

/**
 * Unit test for {@link Strings}.
 *
 * @author Kevin Bourrillion
 */
@NullMarked
@GwtCompatible
public class StringsTest extends TestCase {
  public void testNullToEmpty() {