by will
The designation by will of a person as executor does not operate as a discharge or testamentary disposition of any just claim which the testator had against him, but such claim must be included as an asset of the estate. The executor is liable for the value of the claim when it becomes due, and he must apply and distribute the same in the course of administering the estate. The discharge or disposition of such a claim or of a claim against any other person by will shall be treated as a specific disposition for purposes of 13-1.3. Nothing contained herein precludes an executor from raising any defense to a claim by the estate against him which would be available to any other person against whom the estate has a claim.