System.Security.PermissionListSet.CreateCompressedState C# (CSharp) Method

        static internal PermissionListSet CreateCompressedState(CompressedStack cs, CompressedStack innerCS)
        {
            // function that completes the construction of the compressed stack if not done so already (bottom half for demand evaluation)
            
            bool bHaltConstruction = false;
            if (cs.CompressedStackHandle == null)
                return null; //  FT case or Security off
   
            PermissionListSet pls = new PermissionListSet();
            PermissionSetTriple currentTriple = new PermissionSetTriple();
            int numDomains = CompressedStack.GetDCSCount(cs.CompressedStackHandle);
            for (int i=numDomains-1; (i >= 0 && !bHaltConstruction) ; i--)
            {
                DomainCompressedStack dcs = CompressedStack.GetDomainCompressedStack(cs.CompressedStackHandle, i);
                if (dcs == null)
                    continue; // we hit a FT Domain
                if (dcs.PLS == null)
                {
                    // We failed on some DCS
                    throw new SecurityException(String.Format(CultureInfo.InvariantCulture, Environment.GetResourceString("Security_Generic")));
                }
                pls.UpdateZoneAndOrigin(dcs.PLS);
                pls.Update(currentTriple, dcs.PLS); 
                bHaltConstruction = dcs.ConstructionHalted;
            }
            if (!bHaltConstruction)
            {
                PermissionListSet tmp_pls = null;
                // Construction did not halt. 
                if (innerCS != null)
                {
                    innerCS.CompleteConstruction(null);
                    tmp_pls = innerCS.PLS;
                }
                pls.Terminate(currentTriple, tmp_pls);
            }
            else
            {
                pls.Terminate(currentTriple);
            }

            return pls;
        }