try {
        output.write(b);
      } catch (IOException impossible) {
        throw new AssertionError(impossible);
      }
    }

    @Override
    public void write(byte[] b) {
      try {
        output.write(b);
      } catch (IOException impossible) {
        throw new AssertionError(impossible);
      }
    }

    @Override

            case HALF_UP:
              return (sign(x) >= 0) ? roundCeilingAsDouble : roundFloorAsDouble;
            default:
              throw new AssertionError("impossible");
          }
        }
    }
    throw new AssertionError("impossible");
  }

            case HALF_UP:
              return (sign(x) >= 0) ? roundCeilingAsDouble : roundFloorAsDouble;
            default:
              throw new AssertionError("impossible");
          }
        }
    }
    throw new AssertionError("impossible");
  }

    }
    constructor.setAccessible(true); // accessibility check is too slow
    try {
      return constructor.newInstance();
    } catch (InstantiationException | IllegalAccessException impossible) {
      throw new AssertionError(impossible);
    } catch (InvocationTargetException e) {
      logger.log(Level.WARNING, "Exception while invoking default constructor.", e.getCause());
      return arbitraryConstantInstanceOrNull(type);

    }
    constructor.setAccessible(true); // accessibility check is too slow
    try {
      return constructor.newInstance();
    } catch (InstantiationException | IllegalAccessException impossible) {
      throw new AssertionError(impossible);
    } catch (InvocationTargetException e) {
      logger.log(Level.WARNING, "Exception while invoking default constructor.", e.getCause());
      return arbitraryConstantInstanceOrNull(type);

 *
 * <p>HTML escaping is particularly tricky: For example, <a
 * href="https://www.w3.org/TR/html4/types.html#h-6.2">some elements' text contents must not be HTML
 * escaped</a>. As a result, it is impossible to escape an HTML document correctly without
 * domain-specific knowledge beyond what {@code HtmlEscapers} provides. We strongly encourage the
 * use of HTML templating systems.
 *
 * @author Sven Mawson
 * @author David Beaumont

 * thought of as overkill; however, it's difficult to determine which proper subset of this massive
 * set would be sufficient to expose any possible bug. Brute force is simpler.
 *
 * <p>To use this class the concrete subclass must implement the {@link
 * IteratorTester#newTargetIterator()} method. This is because it's impossible to test an Iterator
 * without changing its state, so the tester needs a steady supply of fresh Iterators.
 *

      if (UPDATE_BB != null) {
        try {
          UPDATE_BB.invokeExact(cs, bb);
        } catch (Throwable e) {
          throwIfUnchecked(e);
          // This should be impossible, since `update` has no `throws` clause.
          throw new UndeclaredThrowableException(e);
        }
        return true;
      } else {
        return false;
      }
    }

    boolean threadStarted = false;
    try {
      startFinalizer.invoke(null, FinalizableReference.class, queue, frqRef);
      threadStarted = true;
    } catch (IllegalAccessException impossible) {
      throw new AssertionError(impossible); // startFinalizer() is public
    } catch (Throwable t) {
      logger.log(
          Level.INFO,
          "Failed to start reference finalizer thread."

  @Override
  public final void run() {
    /*
     * Set runner thread before checking isDone(). If we were to check isDone() first, the task
     * might be cancelled before we set the runner thread. That would make it impossible to
     * interrupt, yet it will still run, since interruptTask will leave the runner value null,
     * allowing the CAS below to succeed.
     */
    Thread currentThread = Thread.currentThread();