code: function (bbox) {
          var min = this.min;
          var max = this.max;
          vec3Copy(min.array, bbox.min.array);
          vec3Copy(max.array, bbox.max.array);
          min._dirty = true;
          max._dirty = true;
          return this;
      }
docs: Copy values from another bounding box
  @param  {clay.BoundingBox} bbox