*   SomeStream stream = new SomeStream("foo");
   *   boolean threw = true;
   *   try {
   *     // ... code which does something with the stream ...
   *     threw = false;
   *   } finally {
   *     // If an exception occurs, rethrow it only if threw==false:
   *     Closeables.close(stream, threw);
   *   }
   * }
   * }</pre>
   *

 *
 * <p>If the precondition is not met, the {@code Preconditions} method throws an unchecked exception
 * of a specified type, which helps the method in which the exception was thrown communicate that
 * its caller has made a mistake. This allows constructs such as
 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   if (value < 0) {
 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }

      throw t;
    }
  }

  /** Calls threadFail with message "should throw exception". */
  public void threadShouldThrow() {
    threadFail("should throw exception");
  }

  /** Calls threadFail with message "should throw" + exceptionName. */
  public void threadShouldThrow(String exceptionName) {
    threadFail("should throw " + exceptionName);
  }

  /**

      cause.setStackTrace(combined);
    }
    if (cause instanceof Exception) {
      throw (Exception) cause;
    }
    if (cause instanceof Error) {
      throw (Error) cause;
    }
    // The cause is a weird kind of Throwable, so throw the outer exception.
    throw e;
  }

  private static Set<Method> findInterruptibleMethods(Class<?> interfaceType) {

      if (!features.contains(methodFeature)) {
        if (stackWithLastReturnedElementAtTop == null) {
          throw PermittedMetaException.UOE_OR_ISE;
        } else {
          throw PermittedMetaException.UOE;
        }
      } else if (stackWithLastReturnedElementAtTop == null) {
        throw PermittedMetaException.ISE;
      }
    }

    private List<E> getElements() {

   *   throwIfUnchecked(failure);
   *   throw new AssertionError(failure);
   * }
   * </pre>
   *
   * @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;
    }
  }

  /**

   *   throwIfUnchecked(failure);
   *   throw new AssertionError(failure);
   * }
   * </pre>
   *
   * @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;
    }
  }

  /**

                        throw new UnsupportedOperationException();
                      }

                      @Override
                      public Iterator<String> iterator() {
                        throw new UnsupportedOperationException();
                      }

                      @Override
                      public boolean removeAll(Collection<?> collection) {

  @DoNotCall("Always throws UnsupportedOperationException")
  public final void putCoalescing(Range<K> range, V value) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the {@code RangeMap} unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @Deprecated
  @Override

  public static class TwoArg {
    /** Action to take on a null param. */
    public enum Action {
      THROW_A_NPE {
        @Override
        public void act() {
          throw new NullPointerException();
        }
      },
      THROW_OTHER {
        @Override
        public void act() {
          throw new FooException();
        }
      },
      JUST_RETURN {
        @Override