guava/src/com/google/common/util/concurrent/FuturesGetChecked.java
@CanIgnoreReturnValue
  static <V, X extends Exception> V getChecked(
      Future<V> future, Class<X> exceptionClass, long timeout, TimeUnit unit) throws X {
    // TODO(cpovirk): benchmark a version of this method that accepts a GetCheckedTypeValidator
    bestGetCheckedTypeValidator().validateClass(exceptionClass);
    try {
      return future.get(timeout, unit);
    } catch (InterruptedException e) {
      currentThread().interrupt();
      throw newWithCause(exceptionClass, e);
    } catch (TimeoutException e) {
      throw newWithCause(exceptionClass, e);
    } catch (ExecutionException e) {
      wrapAndThrowExceptionOrError(e.getCause(), exceptionClass);
      throw new AssertionError();
    }
  }
@CanIgnoreReturnValue
  static <V, X extends Exception> V getChecked(
      Future<V> future, Class<X> exceptionClass, long timeout, TimeUnit unit) throws X {
    // TODO(cpovirk): benchmark a version of this method that accepts a GetCheckedTypeValidator
    bestGetCheckedTypeValidator().validateClass(exceptionClass);
    try {
      return future.get(timeout, unit);
    } catch (InterruptedException e) {
      currentThread().interrupt();
      throw newWithCause(exceptionClass, e);
    } catch (TimeoutException e) {
      throw newWithCause(exceptionClass, e);
    } catch (ExecutionException e) {
      wrapAndThrowExceptionOrError(e.getCause(), exceptionClass);
      throw new AssertionError();
    }
  }
Implementation of {@link Futures#getChecked(Future, Class, long, TimeUnit)}.