text: t = db.array1;
  t.drop();
  
  x = { a : [ 1 , 2 ] };
  
  t.save( { a : [ [1,2] ] } );
  assert.eq( 1 , t.find( x ).count() , "A" );
  
  t.save( x );
  delete x._id;
  assert.eq( 2 , t.find( x ).count() , "B" );
  
  t.ensureIndex( { a : 1 } );
  assert.eq( 2 , t.find( x ).count() , "C" ); // TODO SERVER-146
  