* Cache} interfaces. The {@code asMap} view (and its collection views) have <i>weakly consistent
 * iterators</i>. This means that they are safe for concurrent use, but if other threads modify the
 * cache after the iterator is created, it is undefined which of these changes, if any, are

OkHttp is **not** source-compatible for Kotlin callers, but upgrading should be automatic thanks to
Kotlin’s powerful deprecation features. Most developers should be able to use IntelliJ’s _Code
Cleanup_ for a safe and fast upgrade.


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

#### OkHttpClient final methods

      // it. To preserve FIFO order and failure atomicity of rejected execution when the same
      // Runnable is executed more than once, allocate a wrapper that we know is safe to remove by
      // object identity.
      // A data structure that returned a removal handle from add() would allow eliminating this
      // allocation.
      submittedTask =
          new Runnable() {

      // it. To preserve FIFO order and failure atomicity of rejected execution when the same
      // Runnable is executed more than once, allocate a wrapper that we know is safe to remove by
      // object identity.
      // A data structure that returned a removal handle from add() would allow eliminating this
      // allocation.
      submittedTask =
          new Runnable() {

      /*
       * uncheckedCastNullableTToT is safe: The first call to this method always enters the !hasNext() case and
       * populates key, after which it's never cleared.
       */
      return output(uncheckedCastNullableTToT(key), valueIterator.next());
    }

    @Override
    public void remove() {
      valueIterator.remove();
      /*

Since HTTP requests frequently happen in parallel, connection pooling must be thread-safe.

These are the primary classes involved with establishing, sharing, and terminating connections:

      throw new IllegalArgumentException(e);
    }

    boolean empty;
    if (effectiveRange.isEmpty()) {
      empty = true;
    } else {
      /*
       * requireNonNull is safe because the effectiveRange operations above would have thrown or
       * effectiveRange.isEmpty() would have returned true.
       */
      C afterLower = requireNonNull(range.lowerBound.leastValueAbove(domain));

  }

  /**
   * Returns an array containing all of the elements in the specified collection. This method
   * returns the elements in the order they are returned by the collection's iterator. The returned
   * array is "safe" in that no references to it are maintained by the collection. The caller is
   * thus free to modify the returned array.
   *
   * <p>This method assumes that the collection size doesn't change while the method is running.

  }

  private final class AsMapOfRanges extends IteratorBasedAbstractMap<Range<K>, V> {

    final Iterable<Entry<Range<K>, V>> entryIterable;

    @SuppressWarnings("unchecked") // it's safe to upcast iterables
    AsMapOfRanges(Iterable<RangeMapEntry<K, V>> entryIterable) {
      this.entryIterable = (Iterable) entryIterable;
    }

    @Override
    public boolean containsKey(@Nullable Object key) {

 * Cache} interfaces. The {@code asMap} view (and its collection views) have <i>weakly consistent
 * iterators</i>. This means that they are safe for concurrent use, but if other threads modify the
 * cache after the iterator is created, it is undefined which of these changes, if any, are