def LLTR2domain(lowerleft, topright):
    """Convert the two pairs of (lower, left), (top, right) in (lat, lon)
    into the four pairs of (lat, lon) of the corners """
    xa, ya = lowerleft
    xb, yb = topright
    domain = [(xa, ya), (xa, yb), (xb, yb), (xb, ya)]
    return domain