code: function (v) {
                  if (this._idealKernel === v) {
                      return;
                  }
                  v = Math.max(v, 1);
                  this._idealKernel = v;
                  this._kernel = this._nearestBestKernel(v);
                  this._updateParameters();
              }
docs: Sets the length in pixels of the blur sample region