### Question:
FlexSpacerComponent extends FlexMessageComponent { public void setSize(@Nullable Size size) { this.size = size; } FlexSpacerComponent(); void setSize(@Nullable Size size); @NonNull @Override JSONObject toJsonObject();  }### Answer:
@Test public void with_size() throws JSONException { component = new FlexSpacerComponent(); ((FlexSpacerComponent) component).setSize(FlexMessageComponent.Size.FULL); messageShouldBe("{" + " \"type\": \"spacer\"," + " \"size\": \"full\"" + "}"); }