code: @GwtIncompatible // Class.cast, Class.isInstance
    public static <X extends Throwable> void throwIfInstanceOf(
        Throwable throwable, Class<X> declaredType) throws X {
      checkNotNull(throwable);
      if (declaredType.isInstance(throwable)) {
        throw declaredType.cast(throwable);
      }
    }
docs: Throws {@code throwable} if it is an instance of {@code declaredType}. Example usage:
  
  <pre>
  for (Foo foo : foos) {
  try {
  foo.bar();
  } catch (BarException | RuntimeException | Error t) {
  failure = t;
  }
  }
  if (failure != null) {
  throwIfInstanceOf(failure, BarException.class);
  throwIfUnchecked(failure);
  throw new AssertionError(failure);
  }
  </pre>
  
  @since 20.0