// ------------------------------------------------------------------------
 public static MdaFieldExpr propExpr(MdaField f)
 {
     return new MdaFieldExpr(f);
 }
 public override void switchByType(MdaField field, MdaCompositionTypeVisitor visitor, object value)
 {
     visitor.caseListField(field, value);
 }
 public MdaFieldExpr(MdaField field)
 {
     this.field = field;
 }
 /// <summary>design pattern Visitor</summary>
 /// <param name="field"></param>
 /// <param name="value"></param>
 public abstract void switchByType(MdaField field, MdaCompositionTypeVisitor visitor, object value);