public <T extends @Nullable Object> T[] toArray(T[] array) {
            T[] result = super.toArray(array);
            if (size() < result.length) {
              // It works around a GWT bug where elements after last is not
              // properly null'ed.
              @Nullable Object[] unsoundlyCovariantArray = result;
              unsoundlyCovariantArray[size()] = null;
            }

Backwards-Incompatible Changes
------------------------------

#### OkHttpClient final methods

`OkHttpClient` has 26 accessors like `interceptors()` and `writeTimeoutMillis()` that were non-final
in OkHttp 3.x and are final in 4.x. These were made non-final for use with mocking frameworks like
[Mockito][mockito]. We believe subtyping `OkHttpClient` is the wrong way to test with OkHttp. If

Making and Submitting Changes
--------------

We accept Pull Requests via GitHub. The [developer mailing list][dev-ml-list] is the
main channel of communication for contributors.  
There are some guidelines which will make applying PRs easier for us:
+ Create a topic branch from where you want to base your work (this is usually the master branch).
  Push your changes to a topic branch in your fork of the repository.
+ Make commits of logical units.

    }
  }

  /**
   * Returns a human-readable representation of HTTP/2 frame headers.
   *
   * The format is:
   *
   * ```
   * direction streamID length type flags
   * ```
   *
   * Where direction is `<<` for inbound and `>>` for outbound.
   *
   * For example, the following would indicate a HEAD request sent from the client.
   * ```
   * `<< 0x0000000f    12 HEADERS       END_HEADERS|END_STREAM

     * This can be used to decide whether compression is worthwhile.
     *
     * @param data the data to analyze
     * @param algorithm the compression algorithm
     * @return estimated compression ratio (0.0 to 1.0, where 0.5 means 50% size reduction)
     */
    double estimateCompressionRatio(byte[] data, int algorithm);

    /**
     * Gets the minimum data size threshold for compression.

        smbRandomAccessFile.readFully(buffer);
        assertArrayEquals(new byte[] { 10, 20, 30, 40, 50 }, buffer);
        // Note: There appears to be a bug in the implementation where readFully
        // incorrectly updates the file pointer twice
        assertEquals(10, smbRandomAccessFile.getFilePointer());
    }

     * @return the server's SID
     * @throws CIFSException if there is an error retrieving the server SID
     */
    SID getServerSid(CIFSContext tc, String authorityServerName) throws CIFSException;

    /**
     * This specialized method returns a Map of users and local groups for the
     * target server where keys are SIDs representing an account and each value

import okhttp3.internal.platform.AndroidPlatform
import okhttp3.internal.platform.Platform

/**
 * Modern reflection based SocketAdapter for Conscrypt class SSLSockets.
 *
 * This is used directly for providers where class name is known e.g. the Google Play Provider
 * but we can't compile directly against it, or in fact reliably know if it is registered and
 * on classpath.
 */
open class AndroidSocketAdapter(

 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingSet<E extends @Nullable Object> extends ForwardingCollection<E>
    implements Set<E> {
  // TODO(lowasser): identify places where thread safety is actually lost

  /** Constructor for use by subclasses. */
  protected ForwardingSet() {}

  @Override
  protected abstract Set<E> delegate();

  @Override

   *
   * @see java.util.Collection the definition of general-purpose collections.
   */
  GENERAL_PURPOSE(SUPPORTS_ADD, SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  /** Features supported by collections where only removal is allowed. */
  REMOVE_OPERATIONS(SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  SERIALIZABLE,
  SERIALIZABLE_INCLUDING_VIEWS(SERIALIZABLE),

  SUBSET_VIEW,
  DESCENDING_VIEW,

  /**