T result = uncheckedCastNullableTToT(next);
    next = null;
    return result;
  }

  /**
   * Returns the next element in the iteration without advancing the iteration, according to the
   * contract of {@link PeekingIterator#peek()}.
   *
   * <p>Implementations of {@code AbstractIterator} that wish to expose this functionality should
   * implement {@code PeekingIterator}.
   */
  @ParametricNullness

                    corresponding JSON. But if the data in the object returned is not
                    valid, that would mean a violation of the contract with the client,
                    so it's an error from the API developer. So, FastAPI will raise an
                    error and return a 500 error code (Internal Server Error).

      boolean result = sync.setException(checkNotNull(throwable));
      if (result) {
        executionList.execute();
      }
      return result;
    }

    /**
     * Following the contract of {@link AbstractQueuedSynchronizer} we create a private subclass to
     * hold the synchronizer. This synchronizer is used to implement the blocking and waiting calls

  @Throws(IOException::class)
  abstract fun writeTo(sink: BufferedSink)

  /**
   * A duplex request body is special in how it is **transmitted** on the network and
   * in the **API contract** between OkHttp and the application.
   *
   * This method returns false unless it is overridden by a subclass.
   *
   * ### Duplex Transmission
   *

  private final double sumOfProductsOfDeltas;

  /**
   * Internal constructor. Users should use {@link PairedStatsAccumulator#snapshot}.
   *
   * <p>To ensure that the created instance obeys its contract, the parameters should satisfy the
   * following constraints. This is the callers responsibility and is not enforced here.
   *
   * <ul>
   *   <li>Both {@code xStats} and {@code yStats} must have the same {@code count}.

import java.util.Set;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests representing the contract of {@link Map}. Concrete subclasses of this base class test
 * conformance of concrete {@link Map} subclasses to that contract.
 *
 * @param <K> the type of keys used by the maps under test
 * @param <V> the type of mapped values used the maps under test
 * @author George van den Driessche

            //
            // ---
            //
            // If the CAS fails, the provided callable already started running (or it is about
            // to). Our contract promises:
            //
            // 1. not to execute a new callable until the old one has returned
            //
            // If we were to cancel taskFuture, that would let the next task start while the old

    // They aren't equal...
    assertFalse(hashCodeA.equals(hashCodeB));

    // But they still have the same Object#hashCode() value.
    // Technically not a violation of the equals/hashCode contract, but...?
    assertEquals(hashCodeA.hashCode(), hashCodeB.hashCode());
  }

  public void testRoundTripHashCodeUsingFromString() {
    HashCode hash1 = Hashing.sha1().hashString("foo", US_ASCII);

 * elements, if there is no comparator) to test element equality. As a result, if the comparator is
 * not consistent with equals, some of the standard implementations may violate the {@code Set}
 * contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Louis Wasserman

  }

  // TODO(chrisn): Consider trying to encode/flush directly to the argument byte
  // buffer when possible.
  @Override
  public int read(byte[] b, int off, int len) throws IOException {
    // Obey InputStream contract.
    checkPositionIndexes(off, off + len, b.length);
    if (len == 0) {
      return 0;
    }

    // The rest of this method implements the process described by the CharsetEncoder javadoc.