internal ConstraintStruct(CompiledIdentityConstraint constraint)
 {
     this.constraint     = constraint;
     this.tableDim       = constraint.Fields.Length;
     this.axisFields     = new ArrayList();          // empty fields
     this.axisSelector   = new SelectorActiveAxis(constraint.Selector, this);
     this.qualifiedTable = new Hashtable();
 }
 internal ConstraintStruct (CompiledIdentityConstraint constraint) {
     this.constraint = constraint;
     this.tableDim = constraint.Fields.Length;
     this.axisFields = new ArrayList();              // empty fields
     this.axisSelector = new SelectorActiveAxis (constraint.Selector, this);
     if (this.constraint.Role != CompiledIdentityConstraint.ConstraintRole.Keyref) {
         this.qualifiedTable = new Hashtable();
     }
 }