MySQL 9.3 Release Notes
        
          A MultiSurface is a geometry collection
          composed of surface elements. MultiSurface
          is a noninstantiable class. Its only instantiable subclass is
          MultiPolygon.
        
          MultiSurface
          Assertions
- Surfaces within a - MultiSurfacehave no interiors that intersect.
- Surfaces within a - MultiSurfacehave boundaries that intersect at most at a finite number of points.