public UiTopoLayout scale(double scale) {
        checkArgument(scaleWithinBounds(scale), E_SCALE_OOB);
        this.scale = scale;
        return this;
    }
@Test
    public void setScale() {
        mkRootLayout();
        layout.scale(3.0);
        assertEquals("wrong scale", 3.0, layout.scale(), DELTA);
        layout.scale(0.05);
        assertEquals("wrong scale", 0.05, layout.scale(), DELTA);
    }