title: Remove same repeated points from list<poinf> with lambda expressions
body: <p>I have a list of float points as following:</p>
  
  <pre><code>wayPoints = (new PointF[] { 
  new PointF(18, 0), 
  new PointF(18,0), 
  new PointF(55, 155),
  new PointF(55, 155),
  new PointF(55, 155),
  new PointF(55, 155),
  new PointF(55, 0),
  new PointF(55, 230)}).ToList();
  </code></pre>
  
  <p>I want to use Lambda Expressions in which the same points removed from list but one of those same points stays in the list</p>
  
  <p>Output: </p>
  
  <pre><code>wayPoints = 
  (new PointF[] { 
   new PointF(18, 0),
   new PointF(55, 155),
   new PointF(55, 0),
   new PointF(55, 230)}
  ).ToList();
  </code></pre>
  
  <p>How should I write my commands in Lambda Expressions?</p>