[ServiceOperation()]
public int GetFooCount(string category, IQueryable<Foo> search)
{
    int fooCount;
    if (search != null)
    {
    	IQueryable<Foo> filteredFooSet = this.Context.FooSet.Intersect(search);
    	fooCount = (from foo in filteredFooSet
    	            where foo.Category == category
    	            select foo).Count();
    }
    else
    {
    	fooCount = (from foo in this.Context.ContactSet
    	            where foo.Category == category
    	            select foo).Count();
    }

    return fooCount;
}