box2d — The type representing a 2-dimensional bounding box.
box2d is a spatial data type used to represent
            the two-dimensional bounding box enclosing a geometry or collection of geometries.
            For example, the ST_Extent aggregate function returns a box2d object.
The representation contains the values xmin, ymin, xmax, ymax.
            These are the minimum and maximum values of the X and Y extents.
            
box2d objects have a text representation which looks like BOX(1 2,5 6).