*
   * @since 20.0
   */
  public static void throwIfUnchecked(Throwable throwable) {
    checkNotNull(throwable);
    if (throwable instanceof RuntimeException) {
      throw (RuntimeException) throwable;
    }
    if (throwable instanceof Error) {
      throw (Error) throwable;
    }
  }

  /**
   * Propagates {@code throwable} exactly as-is, if and only if it is an instance of {@link

import static com.google.common.base.Throwables.getCausalChain;
import static com.google.common.base.Throwables.getCauseAs;
import static com.google.common.base.Throwables.getRootCause;
import static com.google.common.base.Throwables.getStackTraceAsString;
import static com.google.common.base.Throwables.lazyStackTrace;
import static com.google.common.base.Throwables.lazyStackTraceIsLazy;

import static com.google.common.base.Throwables.getCausalChain;
import static com.google.common.base.Throwables.getCauseAs;
import static com.google.common.base.Throwables.getRootCause;
import static com.google.common.base.Throwables.getStackTraceAsString;
import static com.google.common.base.Throwables.lazyStackTrace;
import static com.google.common.base.Throwables.lazyStackTraceIsLazy;

import static com.google.common.base.Throwables.throwIfUnchecked;
import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.fail;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Function;
import com.google.common.base.Throwables;
import com.google.common.reflect.AbstractInvocationHandler;

      for (int i = 0; i < reps; i++) {
        int f = 0;
        Throwable t = new Throwable();
        for (StackTraceElement ste : getStackTrace(t)) {
          dummy |= ste == duh;
          if (f++ == breakAt) {
            break;
          }
        }
      }
      return dummy;
    }

    abstract List<StackTraceElement> getStackTrace(Throwable t);
  }

  @BeforeExperiment
  public void doBefore() {

      for (int i = 0; i < reps; i++) {
        int f = 0;
        Throwable t = new Throwable();
        for (StackTraceElement ste : getStackTrace(t)) {
          dummy |= ste == duh;
          if (f++ == breakAt) {
            break;
          }
        }
      }
      return dummy;
    }

    abstract List<StackTraceElement> getStackTrace(Throwable t);
  }

  @BeforeExperiment
  public void doBefore() {

import static com.google.common.base.Throwables.throwIfUnchecked;
import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.fail;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Function;
import com.google.common.base.Throwables;
import com.google.common.reflect.AbstractInvocationHandler;

    @Override
    public void suppress(Closeable closeable, Throwable thrown, Throwable suppressed) {
      suppressions.add(new Suppression(closeable, thrown, suppressed));
    }
  }

  /** Record of a call to suppress. */
  private static class Suppression {
    private final Closeable closeable;
    private final Throwable thrown;
    private final Throwable suppressed;

    @Override
    public void suppress(Closeable closeable, Throwable thrown, Throwable suppressed) {
      suppressions.add(new Suppression(closeable, thrown, suppressed));
    }
  }

  /** Record of a call to suppress. */
  private static class Suppression {
    private final Closeable closeable;
    private final Throwable thrown;
    private final Throwable suppressed;

      } catch (InterruptedException e) {
        // ignore
      }
    }
  }

  /**
   * Cleans up the given reference and any other references already in the queue. Catches and logs
   * all throwables.
   *
   * @return true if the caller should continue to wait for more references to be added to the
   *     queue, false if the associated FinalizableReferenceQueue is no longer referenced.
   */