title: How to graphically represent a UML use case extension point?
body: <p>I have a use case that is associated with two actors in a system. This use case extends another use case, but only one of the actors can use the extended use case.</p>
  
  <p>Is there some way to represent the conditional nature of the extension of the first use case? Or, do I need to specify in the use case documentation that the initial use case can only possibly be extended for one kind of actor?</p>
  
  <p>Thanks.</p>