def getbox(xcenter, ycenter, size=500):
    """
    A function to compute coordinates of a bounding box.

    Arguments:
        - xcenter: int, x position of the center of the box.
        - ycenter: int, y position of the center of the box.
        - size: int, size of the side of the box.

    Returns:
        - box: list of tuple of int, (x, y) coordinates of the sides of the box.
    """
    xo = xcenter - int(size / 2)
    yo = ycenter - int(size / 2)
    xe = xcenter + int(size / 2)
    ye = ycenter + int(size / 2)
    horizonhaut = [(x, yo) for x in range(xo, xe)]
    horizonbas = [(x, ye) for x in range(xo, xe)]
    verticalgauche = [(xo, y) for y in range(yo, ye)]
    verticaldroite = [(xe, y) for y in range(yo, ye)]
    box = horizonbas + horizonhaut + verticaldroite + verticalgauche
    return box