System.Security.Permissions.IsolatedStorageFilePermission.Intersect C# (CSharp) Method

        public override IPermission Intersect(IPermission target)
        {
            if (target == null)
                return null;
            else if (!VerifyType(target))
            {
                throw new 
                    ArgumentException(
                                    String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Argument_WrongType"), this.GetType().FullName)
                                     );
            }

            IsolatedStorageFilePermission operand = (IsolatedStorageFilePermission)target;

            if(operand.IsUnrestricted()) 
                return Copy();
            else if(IsUnrestricted())
                return target.Copy();
            
            IsolatedStorageFilePermission intersection;
            intersection = new IsolatedStorageFilePermission( PermissionState.None );
            intersection.m_userQuota = min(m_userQuota,operand.m_userQuota);    
            intersection.m_machineQuota = min(m_machineQuota,operand.m_machineQuota);   
            intersection.m_expirationDays = min(m_expirationDays,operand.m_expirationDays); 
            intersection.m_permanentData = m_permanentData && operand.m_permanentData;  
            intersection.m_allowed = (IsolatedStorageContainment)min((long)m_allowed,(long)operand.m_allowed);  

            if ((intersection.m_userQuota == 0) &&
            (intersection.m_machineQuota == 0) &&
            (intersection.m_expirationDays == 0) &&
            (intersection.m_permanentData == false) &&
            (intersection.m_allowed == IsolatedStorageContainment.None))
                return null;

            return intersection;
        }
      

		public void Intersect ()
		{
			IsolatedStorageFilePermission empty = new IsolatedStorageFilePermission (PermissionState.None);
			IsolatedStorageFilePermission intersect = (IsolatedStorageFilePermission)empty.Intersect (null);
			Assert.IsNull (intersect, "empty N null");

			intersect = (IsolatedStorageFilePermission)empty.Intersect (empty);
			Assert.IsNull (intersect, "empty N empty");

			IsolatedStorageFilePermission unrestricted = new IsolatedStorageFilePermission (PermissionState.Unrestricted);
			intersect = (IsolatedStorageFilePermission)unrestricted.Intersect (null);
			Assert.IsNull (intersect, "unrestricted N null");

			intersect = (IsolatedStorageFilePermission)unrestricted.Intersect (empty);
			Assert.IsNotNull (intersect, "unrestricted N empty");

			intersect = (IsolatedStorageFilePermission)unrestricted.Intersect (unrestricted);
			Assert.IsNotNull (intersect, "unrestricted N unrestricted");
		}