How to count how many objects will be returned by an ObjectQuery<T>?

string query = "select value obj from Entities.Class as obj " +
                       "where obj.Property = @Value";

        ObjectQuery<Class> oQuery = new ObjectQuery<Class>(query, EntityContext.Instance);
        oQuery.Parameters.Add(new ObjectParameter("Value", someVariable));

int count = oQuery.Count();

int count = oQuery.Count();