// NOTE: If we ever want to use a custom executor here, have a look at CombinedFuture as we'll
    // need to handle RejectedExecutionException

    if (allMustSucceed) {
      // We need fail fast, so we have to keep track of which future failed so we can propagate
      // the exception immediately

      // Register a listener on each Future in the list to update the state of this future.

    // as their length. These files are very small, so it's wasteful to allocate an 8KB buffer.
    int initialBufferSize = min(BUFFER_SIZE, max(128, Integer.highestOneBit(totalLen) * 2));
    // Starting with an 8k buffer, double the size of each successive buffer. Smaller buffers
    // quadruple in size until they reach 8k, to minimize the number of small reads for longer
    // streams. Buffers are retained in a deque so that there's no copying between buffers while

        // so specify this size for test
        return 2000; // you can override as you like it
    }

    protected void throwTooLongBoundarySizeException(final String contentType, final int boundarySize, final int limitSize) {
        final ExceptionMessageBuilder br = new ExceptionMessageBuilder();
        br.addNotice("Too long boundary size so treats it as 404.");
        br.addItem("Advice");

/**
 * A package-local class holding common representation and mechanics for classes supporting dynamic
 * striping on 64bit values. The class extends Number so that concrete subclasses must publicly do
 * so.
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
abstract class Striped64 extends Number {
  /*
   * This class maintains a lazily-initialized table of atomically

@ElementTypesAreNonnullByDefault
public final class MoreExecutors {
  private MoreExecutors() {}

  /**
   * Converts the given ThreadPoolExecutor into an ExecutorService that exits when the application
   * is complete. It does so by using daemon threads and adding a shutdown hook to wait for their
   * completion.
   *
   * <p>This is mainly for fixed thread pools. See {@link Executors#newFixedThreadPool(int)}.
   *

    return state.isCancelled();
  }

  @Override
  public boolean isDone() {
    return state.isDone();
  }

  /*
   * ForwardingFluentFuture needs to override those methods, so they are not final.
   */
  @CanIgnoreReturnValue
  @Override
  public V get() throws InterruptedException, ExecutionException {
    state.maybeThrowOnGet(throwable);
    return value;
  }

 *       than MEDIUM. And so on. These constants are set to conservative values, but even so, if
 *       there is ever any doubt, they can all be increased in one spot to rerun tests on slower
 *       platforms.
 *   <li>All threads generated must be joined inside each test case method (or {@code fail} to do
 *       so) before returning from the method. The {@code joinPool} method can be used to do this

         *            sqrtFloor^2 <= x < (sqrtFloor + 1)^2
         * halfSquare - sqrtFloor <= x < halfSquare + sqrtFloor + 1
         * so |x - halfSquare| <= sqrtFloor.  Therefore, it's safe to treat x - halfSquare as a
         * signed int, so lessThanBranchFree is safe for use.
         */
        return sqrtFloor + lessThanBranchFree(halfSquare, x);
      default:
        throw new AssertionError();
    }

 * ImmutableListMultimap}, which have well-defined {@link #equals} semantics, thus avoiding a common
 * source of bugs and confusion.
 *
 * <p><b>Note:</b> every {@link ImmutableMultimap} offers an {@link #inverse} view, so there is no
 * need for a distinct {@code ImmutableBiMultimap} type.
 *
 * <p><a id="iteration"></a>
 *
 * <p><b>Key-grouped iteration.</b> All view collections follow the same iteration order. In all

      BigInteger x4 = x.shiftLeft(2);
      // sqrt(x) < result + 0.5, so 4 * x < (result + 0.5)^2 * 4
      // (result + 0.5)^2 * 4 = (result^2 + result)*4 + 1
      assertTrue(x4.compareTo(plusHalfSquared) < 0);
      BigInteger minusHalfSquared = result.pow(2).subtract(result).shiftLeft(2).add(ONE);
      // sqrt(x) > result - 0.5, so 4 * x > (result - 0.5)^2 * 4
      // (result - 0.5)^2 * 4 = (result^2 - result)*4 + 1