public AuthorizationPolicy(Term evaluationExpression, Uri policyId, bool delegation, TransformCollection transforms)
        {
            this.Expression = evaluationExpression;
            this.PolicyId   = policyId;
            this.Delegation = delegation;

            if (transforms == null)
            {
                this.Transforms = new TransformCollection();
            }
            else
            {
                this.Transforms = transforms;
            }
        }