2.11.
*   `tf.keras.optimizers.experimental.Optimizer` will graduate in Release 2.11,
    which means `tf.keras.optimizers.Optimizer` will be an alias of
    `tf.keras.optimizers.experimental.Optimizer`. The current
    `tf.keras.optimizers.Optimizer` will continue to be supported as
    `tf.keras.optimizers.legacy.Optimizer`,
    e.g.,`tf.keras.optimizers.legacy.Adam`. Most users won't be affected by this

 *       complicate debugging, lead to unintentional reentrant calls, and force apps to eagerly
 *       initialize all possible subscribers at startup time.
 *   <li>It uses reflection in ways that break when code is processed by optimizers/minimizers like
 *       <a href="https://developer.android.com/studio/build/shrink-code">R8 and Proguard</a>.
 *   <li>It doesn't offer a way to wait for multiple events before taking action. For example, it

    }

    @Override
    boolean isPartialView() {
      return true;
    }

    @Override
    public int size() {
      return entries.size();
    }

    // redeclare to help optimizers with b/310253115
    @SuppressWarnings("RedundantOverride")
    @Override
    @J2ktIncompatible
    @GwtIncompatible
        Object writeReplace() {
      return super.writeReplace();
    }
  }

         * can't use it, this `catch` block might now be necessary only:
         *
         * - in the Android flavor or anywhere else that users might be applying an optimizer that
         * might strip UnsafeComparator entirely. (TODO(cpovirk): Are we confident that optimizers
         * aren't stripping UnsafeComparator today? Should we have Proguard configuration for it?)
         *

          }

          @Override
          ImmutableCollection<Entry<K, V>> delegateCollection() {
            return EntrySet.this;
          }

          // redeclare to help optimizers with b/310253115
          @SuppressWarnings("RedundantOverride")
          @Override
          @J2ktIncompatible
          @GwtIncompatible
                    Object writeReplace() {

    public UnmodifiableIterator<Entry<K, V>> iterator() {
      return multimap.entryIterator();
    }

    @Override
    boolean isPartialView() {
      return false;
    }

    // redeclare to help optimizers with b/310253115
    @SuppressWarnings("RedundantOverride")
    @Override
    @J2ktIncompatible
    @GwtIncompatible
        Object writeReplace() {
      return super.writeReplace();
    }
  }

    public UnmodifiableIterator<Entry<K, V>> iterator() {
      return multimap.entryIterator();
    }

    @Override
    boolean isPartialView() {
      return false;
    }

    // redeclare to help optimizers with b/310253115
    @SuppressWarnings("RedundantOverride")
    @Override
    @J2ktIncompatible
    @GwtIncompatible
        Object writeReplace() {
      return super.writeReplace();
    }
  }

            return true;
          }

          @Override
          public int size() {
            return ImmutableSortedMap.this.size();
          }

          // redeclare to help optimizers with b/310253115
          @SuppressWarnings("RedundantOverride")
          @Override
          @J2ktIncompatible
          @GwtIncompatible
                    Object writeReplace() {

      checkElementIndex(index, size()); // for GWT
      return string.charAt(index);
    }

    @Override
    public int size() {
      return string.length();
    }

    // redeclare to help optimizers with b/310253115
    @SuppressWarnings("RedundantOverride")
    @Override
    @J2ktIncompatible
    @GwtIncompatible
        Object writeReplace() {
      return super.writeReplace();
    }
  }

      checkElementIndex(index, size()); // for GWT
      return string.charAt(index);
    }

    @Override
    public int size() {
      return string.length();
    }

    // redeclare to help optimizers with b/310253115
    @SuppressWarnings("RedundantOverride")
    @Override
    @J2ktIncompatible
    @GwtIncompatible
        Object writeReplace() {
      return super.writeReplace();
    }
  }