def METHOD_NAME():
    radius = 10.
    data = np.ones((50, 50)) * u.adu
    region = CirclePixelRegion(PixCoord(25, 25), radius=radius)
    mask = region.to_mask(mode='exact')
    data_weighted = mask.multiply(data)
    assert data_weighted.unit == u.adu
    assert_almost_equal(np.sum(data_weighted.value), np.pi * radius**2)
    # test that multiply() returns a copy
    data[25, 25] = 100. * u.adu
    assert data_weighted[10, 10].value == 1.