def test_view_of_view_modification():
    adata = ad.AnnData(np.zeros((10, 10)))
    adata[0, :][:, 5:].X = np.ones(5)
    assert np.all(adata.X[0, 5:] == np.ones(5))
    adata[[1, 2], :][:, [1, 2]].X = np.ones((2, 2))
    assert np.all(adata.X[1:3, 1:3] == np.ones((2, 2)))

    adata.X = sparse.csr_matrix(adata.X)
    adata[0, :][:, 5:].X = np.ones(5) * 2
    assert np.all(asarray(adata.X)[0, 5:] == np.ones(5) * 2)
    adata[[1, 2], :][:, [1, 2]].X = np.ones((2, 2)) * 2
    assert np.all(asarray(adata.X)[1:3, 1:3] == np.ones((2, 2)) * 2)
def _add_implementor(rpc_code, blocking, fn):

    # Validate the argument types.
    if type(rpc_code) is not int:
        raise TypeError("Expected int, got %r instead" % type(rpc_code))
    if type(blocking) is not bool:
        raise TypeError("Expected bool, got %r instead" % type(blocking))
    if not callable(fn):
        raise TypeError("Expected callable, got %r instead" % type(fn))

    # Validate the RPC code.
    if rpc_code in rpcMap:
        try:
            msg = "Duplicated RPC implementors for code %d: %s and %s"
            msg %= (rpc_code, rpcMap[rpc_code][0].__name__, fn.__name__)
        except Exception:
            msg = "Duplicated RPC implementors for code: %d" % rpc_code
        raise SyntaxError(msg)

    # TODO: use introspection to validate the function signature

    # Register the implementor.
    rpcMap[rpc_code] = (fn, blocking)

    # Return the implementor. No wrapping is needed! :)
    return fn