@GwtCompatible
@NullMarked
public class Helpers {
  // Clone of Objects.equals
  static boolean equal(@Nullable Object a, @Nullable Object b) {
    return a == b || (a != null && a.equals(b));
  }

  // Clone of Lists.newArrayList
  public static <E extends @Nullable Object> List<E> copyToList(Iterable<? extends E> elements) {
    List<E> list = new ArrayList<>();
    addAll(list, elements);
    return list;
  }

   * removeAll}, and {@code replaceValues} methods return {@code RandomAccess} lists if the factory
   * does. However, the multimap's {@code get} method returns instances of a different class than
   * does {@code factory.get()}.
   *
   * <p>The multimap is serializable if {@code map}, {@code factory}, the lists generated by {@code
   * factory}, and the multimap contents are all serializable.
   *

   * removeAll}, and {@code replaceValues} methods return {@code RandomAccess} lists if the factory
   * does. However, the multimap's {@code get} method returns instances of a different class than
   * does {@code factory.get()}.
   *
   * <p>The multimap is serializable if {@code map}, {@code factory}, the lists generated by {@code
   * factory}, and the multimap contents are all serializable.
   *

      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but

import com.google.common.collect.Iterables;
import com.google.common.collect.LinkedHashMultimap;
import com.google.common.collect.LinkedHashMultiset;
import com.google.common.collect.ListMultimap;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multiset;
import com.google.common.collect.Ordering;
import com.google.common.collect.Range;

 *       java.util.function.Function} is accepted (for example {@link java.util.stream.Stream#map
 *       Stream.map}).
 *   <li><b>Do not</b> call {@link #doForward} or {@link #doBackward} directly; these exist only to
 *       be overridden.
 * </ul>
 *
 * <h3>Example</h3>
 *
 * {@snippet :
 * return Converter.from(
 *     Integer::toHexString,
 *     s -> parseUnsignedInt(s, 16));
 * }
 *

 *  Fix: Don't permit cache iterators to remove entries that are being written.


## Version 4.0.1

_2019-07-10_

 *  Fix: Tolerate null-hostile lists in public API. Lists created with `List.of(...)` don't like it
    when you call `contains(null)` on them!
 *  Fix: Retain binary-compatibility in `okhttp3.internal.HttpHeaders.hasBody()`. Some unscrupulous

        final ProtocolHelper protocolHelper = new ProtocolHelper();

        // Should not throw exception with invalid package
        protocolHelper.loadProtocols("org.invalid.package.does.not.exist");

        // Should have empty arrays initially
        assertEquals(0, protocolHelper.getWebProtocols().length);
        assertEquals(0, protocolHelper.getFileProtocols().length);
    }

purposes of this definition, "submitted" means any form of electronic, 
verbal, or written communication sent to the Licensor or its 
representatives, including but not limited to communication on electronic 
mailing lists, source code control systems, and issue tracking systems that 
are managed by, or on behalf of, the Licensor for the purpose of discussing 
and improving the Work, but excluding communication that is conspicuously 

      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but