def METHOD_NAME():
    da = xr.DataArray(np.arange(30).reshape(5, 6), dims=["x", DATASET_DIM_NAME])
    per_dataset_mean = da.mean("x")
    per_dataset_variance = da.var("x")
    expected = da.var(["x", DATASET_DIM_NAME])
    result = _compute_aggregate_variance(per_dataset_mean, per_dataset_variance)
    xr.testing.assert_allclose(result, expected)