} catch (InterruptedException e) {
              return;
            }
          }
        };
    waiter.start();
    awaitTimedWaiting(waiter);
    service.shutdown();
    Uninterruptibles.joinUninterruptibly(waiter, 10, SECONDS);
    if (waiter.isAlive()) {
      waiter.interrupt();
      fail("awaitTermination failed to trigger after shutdown()");
    }
  }

          return stopwatch.elapsed(MICROSECONDS);
        }

        @Override
        protected void sleepMicrosUninterruptibly(long micros) {
          if (micros > 0) {
            Uninterruptibles.sleepUninterruptibly(micros, MICROSECONDS);
          }
        }
      };
    }
  }

  private static void checkPermits(int permits) {

import static com.google.common.util.concurrent.MoreExecutors.shutdownAndAwaitTermination;
import static com.google.common.util.concurrent.Uninterruptibles.awaitUninterruptibly;
import static com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly;
import static java.util.Arrays.asList;
import static java.util.concurrent.Executors.newSingleThreadExecutor;
import static java.util.concurrent.TimeUnit.SECONDS;

import static com.google.common.util.concurrent.AggregateFuture.ReleaseResourcesReason.OUTPUT_FUTURE_DONE;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly;
import static java.util.Objects.requireNonNull;
import static java.util.logging.Level.SEVERE;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.ImmutableCollection;

import static com.google.common.util.concurrent.MoreExecutors.shutdownAndAwaitTermination;
import static com.google.common.util.concurrent.Uninterruptibles.awaitUninterruptibly;
import static com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly;
import static java.util.Arrays.asList;
import static java.util.concurrent.Executors.newSingleThreadExecutor;
import static java.util.concurrent.TimeUnit.SECONDS;

import static com.google.common.util.concurrent.Futures.transform;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly;
import static java.lang.Math.min;
import static java.util.Collections.unmodifiableSet;
import static java.util.concurrent.TimeUnit.NANOSECONDS;

import com.google.common.annotations.GwtCompatible;

import static com.google.common.util.concurrent.Futures.transform;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly;
import static java.lang.Math.min;
import static java.util.Collections.unmodifiableSet;
import static java.util.concurrent.TimeUnit.NANOSECONDS;

import com.google.common.annotations.GwtCompatible;

      return new Cancellation(false, cancellation);
    } catch (Exception | Error t) { // sneaky checked exception
      return new Failure(t);
    }
  }

  /**
   * An inlined private copy of {@link Uninterruptibles#getUninterruptibly} used to break an
   * internal dependency on other /util/concurrent classes.
   */
  @ParametricNullness
  private static <V extends @Nullable Object> V getUninterruptibly(Future<V> future)

import static com.google.common.util.concurrent.TestPlatform.getDoneFromTimeoutOverload;
import static com.google.common.util.concurrent.Uninterruptibles.awaitUninterruptibly;
import static com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly;
import static com.google.common.util.concurrent.testing.TestingExecutors.noOpScheduledExecutor;
import static java.util.Arrays.asList;

import static com.google.common.util.concurrent.TestPlatform.getDoneFromTimeoutOverload;
import static com.google.common.util.concurrent.Uninterruptibles.awaitUninterruptibly;
import static com.google.common.util.concurrent.Uninterruptibles.getUninterruptibly;
import static com.google.common.util.concurrent.testing.TestingExecutors.noOpScheduledExecutor;
import static java.util.Arrays.asList;