text: 
  mydb = db.getSisterDB( "test_ns1" );
  mydb.dropDatabase();
  
  check = function( n , isNew ){
      var coll = mydb["x" + n];
      if ( isNew ){
          assert.eq( 0 , coll.count() , "pop a: " + n );
          coll.insert( { _id : n } );
      }
      assert.eq( 1 , coll.count() , "pop b: " + n );
      assert.eq( n , coll.findOne()._id , "pop c: " + n );
      return coll;
  }
  
  max = 0;
  
  for ( ; max<1000; max++ ){
      check(max,true);
  }
  
  function checkall( removed ){
      for ( var i=0; i<max; i++ ){
          if ( removed == i ){
              assert.eq( 0 , mydb["x"+i].count() , "should be 0 : " + removed );
          }
          else {
              check( i , false );
          }
      }
  }
  
  checkall();
  
  Random.srand( 123124 );
  its = max / 2;
  print( "its: " + its );
  for ( i=0; i<its; i++ ){
      x = Random.randInt( max );
      check( x , false ).drop();
      checkall( x );
      check( x , true );
      if ( ( i + 1 ) % 20 == 0 ){
          print( i + "/" + its );
      }
  }    
  print( "yay" )
  
  mydb.dropDatabase();
  