docs: function(layers) {
              var lays = [];
              // if passing in no layers
              if (!layers) {
                  lays = [];
              }
              // if passing in an array of Layers
              // NOTE: layers could be an array or Kinetic.Collection.  for simplicity, I'm just inspecting
              // the length property to check for both cases
              else if (layers.length > 0) {
                  lays = layers;
              }
              // if passing in a Layer
              else {
                  lays = [layers];
              }
  
              this.layers = lays;
          }