System.Security.Permissions.IsolatedStoragePermission.max C# (CSharp) Method

        internal static long max(long x,long y) {return x<y?y:x;}
        //------------------------------------------------------

        /// <summary>创建一个权限，该权限是当前权限与指定权限的并集。</summary>
        /// <returns>一个新权限，它表示当前权限与指定权限的并集。</returns>
        /// <param name="target">将与当前权限合并的权限。它必须与当前权限属于同一类型。</param>
        /// <exception cref="T:System.ArgumentException">
        /// <paramref name="target" /> 参数不是 null，而且与当前权限不是同一类型。</exception>
        public override IPermission Union(IPermission target)
        {
            if (target == null)
            {
                return(this.Copy());
            }
            if (!this.VerifyType(target))
            {
                throw new ArgumentException(Environment.GetResourceString("Argument_WrongType", (object)this.GetType().FullName));
            }
            IsolatedStorageFilePermission storageFilePermission1 = (IsolatedStorageFilePermission)target;

            if (this.IsUnrestricted() || storageFilePermission1.IsUnrestricted())
            {
                return((IPermission) new IsolatedStorageFilePermission(PermissionState.Unrestricted));
            }
            IsolatedStorageFilePermission storageFilePermission2 = new IsolatedStorageFilePermission(PermissionState.None);
            long num1 = IsolatedStoragePermission.max(this.m_userQuota, storageFilePermission1.m_userQuota);

            storageFilePermission2.m_userQuota = num1;
            long num2 = IsolatedStoragePermission.max(this.m_machineQuota, storageFilePermission1.m_machineQuota);

            storageFilePermission2.m_machineQuota = num2;
            long num3 = IsolatedStoragePermission.max(this.m_expirationDays, storageFilePermission1.m_expirationDays);

            storageFilePermission2.m_expirationDays = num3;
            int num4 = this.m_permanentData ? 1 : (storageFilePermission1.m_permanentData ? 1 : 0);

            storageFilePermission2.m_permanentData = num4 != 0;
            int num5 = (int)IsolatedStoragePermission.max((long)this.m_allowed, (long)storageFilePermission1.m_allowed);

            storageFilePermission2.m_allowed = (IsolatedStorageContainment)num5;
            return((IPermission)storageFilePermission2);
        }