def cuboid(target, throat_diameter='throat.diameter'):
    """
    Calculate throat cross-sectional area for a cuboid throat

    Parameters
    ----------
    target : OpenPNM Object
        The object which this model is associated with. This controls the
        length of the calculated array, and also provides access to other
        necessary properties.

    throat_diameter : string
        Dictionary key of the throat diameter values

    Returns
    -------
    value : NumPy ndarray
        Array containing throat cross-sectional area values.

    """
    diams = target[throat_diameter]
    value = diams ** 2
    return value
