async def METHOD_NAME(c, s, a, b):
    """Test asynchronous operations."""
    # TODO: use a fixture for this.
    local_registry = UnitRegistry(force_ndarray_like=True)
    da = dask.array.arange(0, 25, chunks=5, dtype=float).reshape((5, 5))
    q = local_registry.Quantity(da, units_)
    x = q + local_registry.Quantity(5, units_)
    y = x.persist()
    assert str(y)
    assert dask.is_dask_collection(y)
    assert len(x.__dask_graph__()) > len(y.__dask_graph__())
    assert not futures_of(x)
    assert futures_of(y)
    future = c.compute(y)
    w = await future
    assert not dask.is_dask_collection(w)
    truth = np.arange(0, 25, dtype=float).reshape((5, 5)) + 5
    assert np.all(truth == w.m)