code: public static Boolean geomDisjoint(Geometry a, Geometry b) {
          if(a==null || b==null) {
              return null;
          }
          return a.disjoint(b);
      }
docs: Return true if the two Geometries are disjoint
  
  @param a Geometry Geometry.
  @param b Geometry instance
  @return true if the two Geometries are disjoint