public GlifVertexParamsStatement(GlifContext context, string from, string to, GlifParameter parameterList)
     : base(context)
 {
     From = from;
     To = to;
     Parameters = parameterList;
 }
 public GlifParameterList(GlifContext context, 
     GlifParameter currentParameter, 
     GlifParameter nextParameter)
     : base(context,currentParameter.Attribute,currentParameter.Value)
 {
     _current = currentParameter;
     _next = nextParameter;
 }