getRanges method
Implementation
Map<String, double> getRanges() {
var ret = <String, double>{};
ret['x'] = loc1.x;
ret['y'] = loc1.y;
ret['z'] = loc1.z;
if (dx >= 0) ret['dx'] = dx;
if (dy >= 0) ret['dy'] = dy;
if (dz >= 0) ret['dz'] = dz;
return ret;
}