/// <summary>
        /// Deep-clone the code object.
        /// </summary>
        public override CodeObject Clone()
        {
            ExternAlias clone = (ExternAlias)base.Clone();

            clone.CloneField(ref clone._rootNamespaceRef, _rootNamespaceRef);
            return(clone);
        }
 /// <summary>
 /// Create a <see cref="Lookup"/> operator.
 /// </summary>
 public Lookup(ExternAlias left, Expression right)
     : base(left.CreateRef(), right)
 {
 }