code: function Feature(input){
      if(input && input.type === "Feature"){
        extend(this, input);
      } else if(input && input.type && input.coordinates) {
        this.geometry = input;
      } else {
        throw "Terraformer: invalid input for Terraformer.Feature";
      }
  
      this.type = "Feature";
    }
docs: /*
  GeoJSON Feature Class
  new Feature();
  new Feature({
  type: "Feature",
  geometry: {
  type: "Polygon",
  coordinates: [ [ [[x,y], [x1,y1]], [[x2,y2], [x3,y3]] ] ]
  }
  });
  new Feature({
  type: "Polygon",
  coordinates: [ [ [[x,y], [x1,y1]], [[x2,y2], [x3,y3]] ] ]
  });