System.Security.Util.SiteString.Union C# (CSharp) Method

        public virtual SiteString Union( SiteString operand )
        {
            if (operand == null)
            {
                return this;
            }
            else if (this.IsSubsetOf( operand ))
            {
                return operand.Copy();
            }
            else if (operand.IsSubsetOf( this ))
            {
                return this.Copy();
            }
            else
            {
                return null;
            }
        }
    }