public override void Initialize(CompilerContext context)
{
base.Initialize(context);
Type builtins = typeof(Boo.Lang.Builtins);
_range_End = Map(builtins.GetMethod("range", new Type[] { Types.Int }));
_range_Begin_End = Map(builtins.GetMethod("range", new Type[] { Types.Int, Types.Int }));
_range_Begin_End_Step = Map(builtins.GetMethod("range", new Type[] { Types.Int, Types.Int, Types.Int }));
}