def get_bbox(x_start, y_start, x_end, y_end):
    """
    This method returns the bounding box of a face.

    Parameters:
    -------------
        x_start: the x value of top-left corner of bounding box
        y_start: the y value of top-left corner of bounding box
        width : the x value of bottom-right corner of bounding box
        height: the y value of bottom-right corner of bounding box

    returns:
    --------------
    [x1, y1, x2, y2, x3, y3, x4, y4]
    the list of x and y values starting from the top-left corner and going clock, or counter-clock wise
    """
    x1 = x_start
    y1 = y_start
    x2 = x_end
    y2 = y_start
    x3 = x_end
    y3 = y_end
    x4 = x_start
    y4 = y_end

    return [x1, y1, x2, y2, x3, y3, x4, y4]