def BC(T):
    """Assign the boundary conditions for the test example solved in this
    module.
    """
    # Along the boundary edges
    T[:, 0] = 100.0
    T[:, -1] = 0.0
    T[0, :] = 0.0
    T[-1, 0] = 0.0

    # Along the boundary vertices
    T[0, 0] = 100.0
    T[-1, 0] = 100.0
    T[0, -1] = 0.0
    T[-1, -1] = 0.0

    return T