return containsKey(key) ? removeFromBothMaps(key) : null;
  }

  @CanIgnoreReturnValue
  @ParametricNullness
  private V removeFromBothMaps(@Nullable Object key) {
    // The cast is safe because the callers of this method first check that the key is present.
    V oldValue = uncheckedCastNullableTToT(delegate.remove(key));
    removeFromInverseMap(oldValue);
    return oldValue;
  }

  override fun request(): Request = originalRequest

  /**
   * Immediately closes the socket connection if it's currently held. Use this to interrupt an
   * in-flight request from any thread. It's the caller's responsibility to close the request body
   * and response body streams; otherwise resources may be leaked.
   *
   * This method is safe to be called concurrently, but provides limited guarantees. If a transport

    @Override
    public List<Long> subList(int fromIndex, int toIndex) {
      return parent.subArray(fromIndex, toIndex).asList();
    }

    /*
     * This is an override that is not directly visible to callers, so NewApi will catch calls to
     * Collection.spliterator() where necessary.
     */
    @IgnoreJRERequirement
    @Override
    public Spliterator.OfLong spliterator() {
      return parent.spliterator();

   * avoid memory leaks when an element is no longer necessary.
   *
   * <p>This method accepts an array with element type {@code @Nullable T}, but callers must pass an
   * array whose contents are initially non-null. The {@code @Nullable} annotation indicates that
   * this method will write nulls into the array during iteration.
   *

    }
  }

  /*
   * For a discussion of the signature of verifyNotNull, see the discussion above
   * Preconditions.checkNotNull.
   *
   * (verifyNotNull has many fewer "problem" callers, so we could try to be stricter. On the other
   * hand, verifyNotNull arguably has more reason to accept nullable arguments in the first
   * place....)
   */

  /**

  /*
   * The following methods are safe to call as long as both of the following hold:
   *
   * - allocArrays() has been called. Callers can confirm this by checking needsAllocArrays().
   *
   * - The map has not switched to delegating to a java.util implementation to mitigate hash
   *   flooding. Callers can confirm this by null-checking delegateOrNull().
   *

            }

            if (closed) {
              throw IOException("stream closed")
            } else if (readBuffer.size > 0L) {
              // Prepare to read bytes. Start by moving them to the caller's buffer.
              readBytesDelivered = readBuffer.read(sink, minOf(byteCount, readBuffer.size))
              readBytes.update(total = readBytesDelivered)

  public final <S extends @Nullable T> Equivalence<Iterable<S>> pairwise() {
    // Ideally, the returned equivalence would support Iterable<? extends T>. However,
    // the need for this is so rare that it's not worth making callers deal with the ugly wildcard.
    return new PairwiseEquivalence<>(this);
  }

  /**
   * Returns a predicate that evaluates to true if and only if the input is equivalent to {@code

        node.previousSibling = keyTail;
        keyList.tail = node;
      }
    } else { // non-empty list, insert before nextSibling
      /*
       * requireNonNull is safe as long as callers pass a nextSibling that (a) has the same key and
       * (b) is present in the multimap. (And they do, except maybe in case of concurrent
       * modification, in which case all bets are off.)
       */

    /**
     * It is implicitly assumed that all the services are NEW and that they will all remain NEW
     * until all the Listeners are installed and {@link #markReady()} is called. It is our caller's
     * responsibility to only call {@link #markReady()} if all services were new at the time this
     * method was called and when all the listeners were installed.
     */