* to this function.
   *
   * <p><b>Warning: do not depend</b> on the behavior of this method.
   *
   * <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

   * to this function.
   *
   * <p><b>Warning: do not depend</b> on the behavior of this method.
   *
   * <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

 *       under our current constraints.
 *   <li>NullAway, which will <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
 *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
 *       you can set {@code

 *       under our current constraints.
 *   <li>NullAway, which will <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
 *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
 *       you can set {@code

/**
 * The presence of this annotation on an API indicates that the method may not be used with
 * the <a href="http://www.gwtproject.org/">Google Web Toolkit</a> (GWT).
 *
 * <p>This annotation behaves identically to <a href=
 * "http://www.gwtproject.org/javadoc/latest/com/google/gwt/core/shared/GwtIncompatible.html">the
 * {@code @GwtIncompatible} annotation in GWT itself</a>.
 *
 * @author Charles Fry
 */

/**
 * The presence of this annotation on an API indicates that the method may not be used with
 * the <a href="http://www.gwtproject.org/">Google Web Toolkit</a> (GWT).
 *
 * <p>This annotation behaves identically to <a href=
 * "http://www.gwtproject.org/javadoc/latest/com/google/gwt/core/shared/GwtIncompatible.html">the
 * {@code @GwtIncompatible} annotation in GWT itself</a>.
 *
 * @author Charles Fry
 */

 *       under our current constraints.
 *   <li>NullAway, which will <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
 *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
 *       you can set {@code

 *       under our current constraints.
 *   <li>NullAway, which will <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
 *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
 *       you can set {@code

 *       under our current constraints.
 *   <li>NullAway, which will <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
 *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
 *       you can set {@code

 *       under our current constraints.
 *   <li>NullAway, which will <a
 *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
 *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
 *       you can set {@code