title: How to clear a cesium map before attempting to redraw points
body: <p>I am sending points to a cesium map and trying to make the points move from one location to the other. I am trying to clear the map before adding my points but what I have does not work.  What is the best way to clear the map of points,etc.
  It seems like it would work but the only way I can sometimes see the correct points is to do browser refresh . Thanks</p>
  
  <pre><code>var viewer   = new Cesium.Viewer('cesiumContainer', { infoBox : false });
  var scene    = viewer.scene;
  var points   = scene.primitives.add(new Cesium.PointPrimitiveCollection());
  var entities = viewer.entities;
  var entity = "";
  </code></pre>
  
  <p>...</p>
  
  <pre><code>entities.removeAll();
  points.removeAll();
  </code></pre>