stream.takeHeaders()
    }
    val elapsedNanos = System.nanoTime() - startNanos
    awaitWatchdogIdle()
    // 200ms delta
    assertThat(TimeUnit.NANOSECONDS.toMillis(elapsedNanos).toDouble())
      .isCloseTo(500.0, 200.0)
    assertThat(connection.openStreamCount()).isEqualTo(0)

    // Verify the peer received what was expected.
    assertThat(peer.takeFrame().type).isEqualTo(Http2.TYPE_HEADERS)

                if (value instanceof final Number num) {
                    value = num.doubleValue();
                } else {
                    value = DfTypeUtil.toDouble(value.toString());
                }
            }
            return new Pair<>(key, value);
        }).collect(Collectors.toMap(Pair::getFirst, Pair::getSecond));
    }

    val response1 = get(server.url("/a"))
    assertThat(response1.body.string()).isEqualTo("A")
    assertThat(response1.header("Allow")).isNull()
    assertThat((response1.receivedResponseAtMillis - t0).toDouble()).isCloseTo(0.0, 250.0)

    // A conditional cache hit updates the cache.
    Thread.sleep(500) // Make sure t0 and t1 are distinct.
    val t1 = System.currentTimeMillis()

        "stream was reset: PROTOCOL_ERROR",
      )
    }
    val elapsedUntilFailure = System.nanoTime() - executeAtNanos
    assertThat(TimeUnit.NANOSECONDS.toMillis(elapsedUntilFailure).toDouble())
      .isCloseTo(1000.0, 250.0)

    // Confirm a single ping was sent but not acknowledged.
    val logs = testLogHandler.takeAll()
    assertThat(countFrames(logs, "FINE: >> 0x00000000     8 PING          "))

   * could use null, but that messes with our nullness checking, including under J2KT. We could
   * probably work around it by changing how we annotate the J2CL EnumMap, but that's probably more
   * trouble than just using Object.class.)
   *
   * Then we declare the getters for these fields as @GwtIncompatible so that no one can try to use
   * them under J2CL—or, as an unfortunate side effect, under GWT. We do still give the fields

            called[0] = true;
          }

          @Override
          public void onFailure(Throwable t) {}
        },
        directExecutor());
    assertThat(called[0]).isTrue();
  }

  // Avoid trouble with automatic mapping between JRE and Kotlin runtime classes.
  static class CustomRuntimeException extends RuntimeException {}

  public void testCatching() throws Exception {
    FluentFuture<?> f =

        /*
         * I'm not sure that we could actually get here for *Android*: I would expect us to enter
         * the POSIX code path instead. And if we tried this code path, we'd have trouble unless we
         * were running under a new enough version of Android to support NIO.
         *
         * So this is probably just the "Windows Java 8" case. In that case, if we wanted *another*

      Supplier<T> delegate, Duration duration) {
    checkNotNull(delegate);
    // The alternative of `duration.compareTo(Duration.ZERO) > 0` causes J2ObjC trouble.
    checkArgument(
        !duration.isNegative() && !duration.isZero(), "duration (%s) must be > 0", duration);
    return new ExpiringMemoizingSupplier<>(delegate, toNanosSaturated(duration));
  }

   *       collections intelligently fall back to a binary search tree if hash table collisions are
   *       detected. Rather than going to all the trouble of reimplementing this ourselves, we
   *       simply switch over to use the JDK implementation wholesale if probable hash flooding is
   *       detected, sacrificing the compactness guarantee in very rare cases in exchange for much

      Supplier<T> delegate, Duration duration) {
    checkNotNull(delegate);
    // The alternative of `duration.compareTo(Duration.ZERO) > 0` causes J2ObjC trouble.
    checkArgument(
        !duration.isNegative() && !duration.isZero(), "duration (%s) must be > 0", duration);
    return new ExpiringMemoizingSupplier<>(delegate, toNanosSaturated(duration));
  }