import org.jspecify.annotations.Nullable;

/**
 * An abstract implementation of {@link Hasher}, which only requires subtypes to implement {@link
 * #putByte}. Subtypes may provide more efficient implementations, however.
 *
 * @author Dimitris Andreou
 */
abstract class AbstractHasher implements Hasher {
  @Override
  @CanIgnoreReturnValue
  public final Hasher putBoolean(boolean b) {
    return putByte(b ? (byte) 1 : (byte) 0);

   */
  public PatternFilenameFilter(Pattern pattern) {
    this.pattern = Preconditions.checkNotNull(pattern);
  }

  /*
   * Our implementation works fine with a null `dir`. However, there's nothing in the documentation
   * of the supertype that suggests that implementations are expected to tolerate null. That said, I
   * see calls in Google code that pass a null `dir` to a FilenameFilter.... So let's declare the

   * the backport does. For now, we're keeping the class declaration in *both* flavors so that both
   * flavors can read old data or data from the other flavor. However, we strongly discourage
   * relying on this, as we have made incompatible changes to serialized forms in the past and
   * expect to do so again, as discussed in https://github.com/google/guava#important-warnings.
   */

    for details.

    The summary is that it ignores one file in favor of the other.
    util.concurrent, like nearly all our packages, has two .gwt.xml files: one
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

    GWT happens to use the prod .gwt.xml, so it looks for no supersource for

   * xStats().populationVariance() > 0.0 && yStats().populationVariance() > 0.0}). The result is not
   * guaranteed to be exactly +/-1 even when the data are perfectly (anti-)correlated, due to
   * numerical errors. However, it is guaranteed to be in the inclusive range [-1, +1].
   *
   * <h3>Non-finite values</h3>
   *
   * <p>If the dataset contains any non-finite values ({@link Double#POSITIVE_INFINITY}, {@link

   *
   * <p>Historically, {@code Supplier} instances in this library have implemented this method to
   * recognize certain cases where distinct {@code Supplier} instances would in fact behave
   * identically. However, as code migrates to {@code java.util.function}, that behavior will
   * disappear. It is best not to depend on it.
   */
  @Override
  boolean equals(@Nullable Object object);

 *       OptionalLong} and {@code OptionalDouble}, the use of which is recommended; Guava does not
 *       have these.
 * </ul>
 *
 * <p><b>There are no plans to deprecate this class in the foreseeable future.</b> However, we do
 * gently recommend that you prefer the new, standard Java class whenever possible.
 *
 * <p>See the Guava User Guide article on <a

   *
   * <p>This method is significantly faster than {@link String#equalsIgnoreCase} and should be used
   * in preference if at least one of the parameters is known to contain only ASCII characters.
   *
   * <p>Note however that this method does not always behave identically to expressions such as:
   *
   * <ul>
   *   <li>{@code string.toUpperCase().equals("UPPER CASE ASCII")}
   *   <li>{@code string.toLowerCase().equals("lower case ascii")}

import org.jspecify.annotations.Nullable;

/**
 * An abstract implementation of {@link Hasher}, which only requires subtypes to implement {@link
 * #putByte}. Subtypes may provide more efficient implementations, however.
 *
 * @author Dimitris Andreou
 */
abstract class AbstractHasher implements Hasher {
  @Override
  @CanIgnoreReturnValue
  public final Hasher putBoolean(boolean b) {
    return putByte(b ? (byte) 1 : (byte) 0);

   *
   * <p>Historically, {@code Function} instances in this library have implemented this method to
   * recognize certain cases where distinct {@code Function} instances would in fact behave
   * identically. However, as code migrates to {@code java.util.function}, that behavior will
   * disappear. It is best not to depend on it.
   */
  @Override
  boolean equals(@Nullable Object obj);