* best we can do (since logging may overflow the stack) is to let the error propagate. Because
     * it is an Error, it won't be caught and logged by AbstractFuture.executeListener. Instead, it
     * can propagate through many layers of AbstractTransformFuture up to the root call to set().
     *
     * https://github.com/google/guava/issues/2254
     *
     * Other kinds of Errors are possible:
     *

  /**
   * The elements in this map would pass the UNDER test, but are known not to be public suffixes and
   * are thus excluded from consideration. Since it refers to elements in UNDER of the same type,
   * the type is actually not important here. The map is simply used for consistency reasons.
   */
  public static final ImmutableMap<String, PublicSuffixType> EXCLUDED =