title: Does a relation (aggregation, composition) replace an attribute?
body: <p>I'm pretty new at UML modelling so bear with me.</p>
  
  <p>Say I have a class with an attribute <code>students</code> that is a list of <code>Student</code> instances. I have set an aggregation relation to the <code>Student</code> class which is also in the diagram. Does this relation <i>replace</i> an attribute entry such as <code>#students : Student[]</code> in the container class, or can the attribute and relation co-exist?</p>
  
  <p>Thanks in advance for any answers!</p>