> Polygons.deny({update: function() { return true; }});
> p=Polygons.findOne();
{ _id: '74iGubCqxB29ZF2tJ',
  geom: 
   { type: 'Polygon',
     coordinates: [ [Object] ],
     type2: 'Polygonal' },
  tags: {} }
> Polygons.update({_id: p._id}, {$set: {'geom.type2': 'Polygonify'}})
1
> Polygons.findOne(p._id)
{ _id: '74iGubCqxB29ZF2tJ',
  geom: 
   { type: 'Polygon',
     coordinates: [ [Object] ],
     type2: 'Polygonify' },
  tags: {} }
>