title: C# Distinct with ability to choose which object to save, which ones to remove
body: <p>I implemented this comparer which works OK.</p>
  
  <pre><code>class ReservationDatesDistinctComparer : IEqualityComparer&lt;ReservationModel&gt;
  {
      public bool Equals(ReservationModel x, ReservationModel y)
      {
          return x.FromDate.Date== y.FromDate.Date &amp;&amp; x.ToDate.Date == y.ToDate.Date &amp;&amp; x.UnitId == x.UnitId;
      }
  
      public int GetHashCode(ReservationModel product)
      {  
          int hashProductCode = 1;
          return  hashProductCode;
      }
  }
  </code></pre>
  
  <p>But on <code>ReservationModel</code> I have some other property let's call it <code>ReservationType</code> and I would like to filter out with distinct same dates but keep only <code>ReservationModel</code> who has Type A not Type B.</p>
  
  <p>How it is posible to affect on <code>Distinct</code> which model it will choose?</p>