old_contents: 
  db = connect( "tests" ); 
  
  t1 = db.table1; 
  t2 = db.table2; 
  
  o1 = {a: 'a', b: "b"}; 
  o2 = {e: 'e', o: o1}; 
  
  t1.save(o1); 
  t2.save(o2); 
  
  o1 = null; 
  o2 = null; 
  o2 = t2.findOne(); 
  
  assert( "a" == o2.o.a);
  assert( "b" == o2.o.b); 
  
  o1 = o2.o; 
  o1.a = "c"; 
  
  delete o1._id; 
  delete o1._ns; 
  
  db.asd.save( o1 );
  
  
  
new_contents: 
  db = connect( "tests" ); 
  
  t1 = db.table1; 
  t2 = db.table2; 
  
  t1.remove( {} );
  t2.remove( {} );
  
  o1 = {a: 'a', b: "b"}; 
  o2 = {e: 'e', o: o1}; 
  
  t1.save(o1); 
  t2.save(o2); 
  
  origo1id = o1._id;
  
  o1 = null; 
  o2 = null; 
  o2 = t2.findOne(); 
  
  print( tojson( o2 ) );
  
  assert( "a" == o2.o.a);
  assert( "b" == o2.o.b); 
  
  o1 = o2.o; 
  o1.a = "c"; 
  
  t2.save(o2);
  
  assert( t2.findOne( o2._id ).o.a == "c" );
  assert( t2.findOne( o2._id ).o._id == origo1id );
  assert( t1.findOne( origo1id ).a == "c" );
  
  
  
subject: make test better