ShapeContainerMixin.createStroke

createStroke(opts: StrokeOptions): Stroke;

// Add a solid black stroke
layer.createStroke({
  fill: { type: "SOLID", color: { r: 0, g: 0, b: 0 } },
  width: 2,
});

// Add a gradient stroke
layer.createStroke({
  fill: {
    type: "GRADIENT_LINEAR",
    stops: [
      { color: { r: 255, g: 0, b: 0 }, offset: 0, opacity: 1 },
      { color: { r: 0, g: 0, b: 255 }, offset: 1, opacity: 1 },
    ],
  },
  width: 5,
});