code: public MethodHandle throwException() {
          if (type().parameterCount() != 1 || !Throwable.class.isAssignableFrom(type().parameterType(0))) {
              throw new InvalidTransformException("incoming signature must have one Throwable type as its sole argument: " + type());
          }
          return invoke(MethodHandles.throwException(type().returnType(), type().parameterType(0).asSubclass(Throwable.class)));
      }
docs: Throw the current signature's sole Throwable argument. Return type
  does not matter, since it will never return.
  
  @return a handle that has all transforms applied and which will eventually throw an exception