def METHOD_NAME(x):
    """
    Let's say that we only want to search the space in which some combinations of
    variables are not allowed. We can't implement this using just bounds, hence we need
    to add some constraints in.
    All we're effectively doing here is chopping the search space rectangle, and saying
    that:
        x1 + x2 < 3
        x2 - 2x1 > 1
    """
    constraint = np.zeros(2)
    constraint[0] = (x[0] + x[1]) - 3
    constraint[1] = (-2 * x[0] + x[1]) + 1
    return constraint