title: VBA: is there something like Abstract Class?
body: <p>I'm using an interface to ensure some similar classes implements some mandatory methods (subs/functions). </p>
  
  <p>Example:</p>
  
  <ul>
  <li>interface I1 declares M1 and M2 methods</li>
  <li>C1 and C2 implement I1, and have their own versions for M1 and M2.</li>
  </ul>
  
  <p>C1 and C2 also need methods that are exactly the same, for example methods SM1 and SM2.</p>
  
  <p>To avoid repeating SM1 and SM2 I'd like to define an abstract class AC:</p>
  
  <ul>
  <li>implementing I1</li>
  <li>defining SM1 and SM2.</li>
  </ul>
  
  <p>which would be extended by C1 and C2</p>
  
  <p>This solution is indeed possible in Java, but I don't find any documentation for doing the same in VBA. (VB.Net seems to allow abstract classes using keyword MustInherit.)</p>
  
  <p><strong>Any confirmation it is possible or not in VBA?</strong></p>