Why is it that an overridden method can't throw a new checked Exception
<p>I have two questions :</p>

<ol>
<li>What is the purpose of the constraint that an overridden method can't throw a new checked exception?</li>
<li>Why it is allowed that an overridden method can only throw all or none, or a subset of the checked exceptions that are specified in the throws clause of the overridden method in the superclass?</li>
</ol>
