public ExpressionExternMember(Aggregation _aggr, string name, bool isStatic)
     : base(null, null)
 {
     aggregation = _aggr;
     Name = name;
     IsStatic = isStatic;
 }
 public ExpressionExternConstant(Aggregation _aggr, string name)
     : base(_aggr, name, true)
 {
 }
 public ExpressionExternMethod(Aggregation _aggr, string name, bool isStatic, params ExpressionNode[] nodes)
     : base(_aggr, name, isStatic)
 {
     Params = nodes;
 }
 public ExpressionExternMethod(Aggregation _aggr, string name, bool isStatic, params ExpressionNode[] nodes)
     : base(_aggr, name, isStatic)
 {
     Params = nodes;
 }
 public ExpressionExternConstant(Aggregation _aggr, string name)
     : base(_aggr, name, true)
 {
 }