ZeroInstall.Publish.Capture.SnapshotDiff.CollectProtocolAssocsEx C# (CSharp) Method

        private static void CollectProtocolAssocsEx([NotNull] RegistryKey capsKey, [NotNull] CommandMapper commandMapper, [NotNull] CapabilityList capabilities)
        {
            #region Sanity checks
            if (capsKey == null) throw new ArgumentNullException(nameof(capsKey));
            if (commandMapper == null) throw new ArgumentNullException(nameof(commandMapper));
            if (capabilities == null) throw new ArgumentNullException(nameof(capabilities));
            #endregion

            using (var urlAssocKey = capsKey.OpenSubKey(DesktopIntegration.Windows.AppRegistration.RegSubKeyUrlAssocs))
            {
                if (urlAssocKey == null) return;

                foreach (string protocol in urlAssocKey.GetValueNames())
                {
                    string progID = urlAssocKey.GetValue(protocol, "").ToString();
                    using (var progIDKey = Registry.ClassesRoot.OpenSubKey(progID))
                    {
                        if (progIDKey == null) continue;

                        var prefix = new KnownProtocolPrefix {Value = protocol};
                        var existing = capabilities.GetCapability<UrlProtocol>(progID);
                        if (existing == null)
                        {
                            var capability = new UrlProtocol
                            {
                                ID = progID,
                                Descriptions = {progIDKey.GetValue("", "").ToString()},
                                KnownPrefixes = {prefix}
                            };
                            capability.Verbs.AddRange(GetVerbs(progIDKey, commandMapper));
                            capabilities.Entries.Add(capability);
                        }
                        else existing.KnownPrefixes.Add(prefix);
                    }
                }
            }
        }
        #endregion