text: "use strict";
  
  /*The following list has ghost coordinates for voronoi cells that surround
  the real BlueTruth sensors. We create ghost voronoi cells so that the real 
  cells would not divide the entire map.*/
  var boundary_sites = [{
      "lat": 52.24861,
      "lng": 0.11536,
      "x": null,
      "y": null
  }, 
  {
      "lat": 52.2503,
      "lng": 0.14763,
      "x": null,
      "y": null
  },
  {
      "lat": 52.24735,
      "lng": 0.17681,
      "x": null,
      "y": null
  }, 
  {
      "lat": 52.2339,
      "lng": 0.20153,
      "x": null,
      "y": null
  },
  
  {
      "lat": 52.21139,
      "lng": 0.21286,
      "x": null,
      "y": null
  }, 
  {
      "lat": 52.18993,
      "lng": 0.2029,
      "x": null,
      "y": null
  },
  
  {
      "lat": 52.16425,
      "lng": 0.1902,
      "x": null,
      "y": null
  }, 
  {
      "lat": 52.15034,
      "lng": 0.16342,
      "x": null,
      "y": null
  },
  
  {
      "lat": 52.1398,
      "lng": 0.12051,
      "x": null,
      "y": null
  }, 
  {
      "lat": 52.15456,
      "lng": 0.08205,
      "x": null,
      "y": null
  },
  
  {
      "lat": 52.16572,
      "lng": 0.06111,
      "x": null,
      "y": null
  }, 
  {
      "lat": 52.1813,
      "lng": 0.03571,
      "x": null,
      "y": null
  },
  
  {
      "lat": 52.20634,
      "lng": 0.01648,
      "x": null,
      "y": null
  }, 
  {
      "lat": 52.22464,
      "lng": 0.02884,
      "x": null,
      "y": null
  },
  
  {
      "lat": 52.23726,
      "lng": 0.05527,
      "x": null,
      "y": null
  },
  {
      "lat": 52.24441,
      "lng": 0.08446,
      "x": null,
      "y": null
  }
  ];
  