title: Entity Validation in Sharp Architecture Repository
body: <p>I have created a new 1.6 Sharp Architecture project.</p>
  
  <p>I have marked my only Entity with HasUniqueDomainSignatureAttribute and one string property marked DomainSignatureAttribute.</p>
  
  <p>I create 2 entities with the same DomainSignature and I'm able to save them both thous having duplicates.</p>
  
  <p>Am I missing some configuration? As I was under the impression that this would work out of the box.</p>