AABB = function(a, b) {
            if (a === undefined) {
              Vec3D.call(this);
              this.setExtent(new Vec3D());
            } else if (typeof a == "number") {
              Vec3D.call(this, new Vec3D());
              this.setExtent(a);
            } else if (internals.has.XYZ(a)) {
              Vec3D.call(this, a);
              if (b === undefined && internals.is.AABB(a)) {
                this.setExtent(a.getExtent());
              } else {
                if (typeof b == "number") {
                  this.setExtent(new Vec3D(b, b, b));
                } else {
                  //should be an AABB
                  this.setExtent(b);
                }
              }
            }
          }
@class Axis-aligned Bounding Box
 @member