private void LazyInitialize()
        {
            if (_isInitialized)
            {
                return;
            }

            _isInitialized = true;

            // Crack the search path just one time.
            Match match = s_crackAssemblyFoldersExSentinel.Value.Match(this.searchPathElement);

            _wasMatch = false;

            if (match.Success)
            {
                _registryKeyRoot      = match.Groups["REGISTRYKEYROOT"].Value.Trim();
                _targetRuntimeVersion = match.Groups["TARGETRUNTIMEVERSION"].Value.Trim();
                _registryKeySuffix    = match.Groups["REGISTRYKEYSUFFIX"].Value.Trim();
                _osVersion            = null;
                _platform             = null;
                Group conditions = match.Groups["CONDITIONS"];

                // Disregard if there are any empty values in the {Registry} tag.
                if (_registryKeyRoot.Length != 0 && _targetRuntimeVersion.Length != 0 && _registryKeySuffix.Length != 0)
                {
                    // Tolerate version keys that don't begin with "v" as these could come from user input
                    if (!_targetRuntimeVersion.StartsWith("v", StringComparison.OrdinalIgnoreCase))
                    {
                        _targetRuntimeVersion = _targetRuntimeVersion.Insert(0, "v");
                    }

                    if (conditions?.Value != null && conditions.Length > 0 && conditions.Value.Length > 0)
                    {
                        string value = conditions.Value.Trim();

                        // Parse the condition statement for OSVersion and Platform
                        foreach (string c in value.Split(MSBuildConstants.ColonChar))
                        {
                            if (String.Compare(c, 0, "OSVERSION=", 0, 10, StringComparison.OrdinalIgnoreCase) == 0)
                            {
                                _osVersion = c.Substring(10);
                            }
                            else if (String.Compare(c, 0, "PLATFORM=", 0, 9, StringComparison.OrdinalIgnoreCase) == 0)
                            {
                                _platform = c.Substring(9);
                            }
                        }
                    }
                    _wasMatch = true;

                    bool   useCache = Environment.GetEnvironmentVariable("MSBUILDDISABLEASSEMBLYFOLDERSEXCACHE") == null;
                    string key      = "ca22615d-aa83-444b-80b9-b32f3d5db097" + this.searchPathElement;
                    if (useCache && _buildEngine != null)
                    {
                        _assemblyFoldersCache = _buildEngine.GetRegisteredTaskObject(key, RegisteredTaskObjectLifetime.Build) as AssemblyFoldersExCache;
                    }

                    if (_assemblyFoldersCache == null)
                    {
                        AssemblyFoldersEx assemblyFolders = new AssemblyFoldersEx(_registryKeyRoot, _targetRuntimeVersion, _registryKeySuffix, _osVersion, _platform, _getRegistrySubKeyNames, _getRegistrySubKeyDefaultValue, this.targetProcessorArchitecture, _openBaseKey);
                        _assemblyFoldersCache = new AssemblyFoldersExCache(assemblyFolders, fileExists);
                        if (useCache)
                        {
                            _buildEngine?.RegisterTaskObject(key, _assemblyFoldersCache, RegisteredTaskObjectLifetime.Build, true /* dispose early ok*/);
                        }
                    }

                    fileExists = _assemblyFoldersCache.FileExists;
                }
            }
        }
        /// <summary>
        /// Initialize this class if it hasn't been initialized yet.
        /// </summary>
        private void LazyInitialize()
        {
            if (_isInitialized)
                return;

            _isInitialized = true;

            // Crack the search path just one time.
            Match match = s_crackAssemblyFoldersExSentinel.Match(this.searchPathElement);
            _wasMatch = false;

            if (match.Success)
            {
                _registryKeyRoot = match.Groups["REGISTRYKEYROOT"].Value.Trim();
                _targetRuntimeVersion = match.Groups["TARGETRUNTIMEVERSION"].Value.Trim();
                _registryKeySuffix = match.Groups["REGISTRYKEYSUFFIX"].Value.Trim();
                _osVersion = null;
                _platform = null;
                Group conditions = match.Groups["CONDITIONS"];

                // Disregard if there are any empty values in the {Registry} tag.
                if (_registryKeyRoot.Length != 0 && _targetRuntimeVersion.Length != 0 && _registryKeySuffix.Length != 0)
                {
                    // Tolerate version keys that don't begin with "v" as these could come from user input
                    if (!_targetRuntimeVersion.StartsWith("v", StringComparison.OrdinalIgnoreCase))
                    {
                        _targetRuntimeVersion = _targetRuntimeVersion.Insert(0, "v");
                    }

                    if (conditions != null && conditions.Value != null && conditions.Length > 0 && conditions.Value.Length > 0)
                    {
                        string value = conditions.Value.Trim();

                        // Parse the condition statement for OSVersion and Platform
                        foreach (string c in value.Split(':'))
                        {
                            if (String.Compare(c, 0, "OSVERSION=", 0, 10, StringComparison.OrdinalIgnoreCase) == 0)
                            {
                                _osVersion = c.Substring(10);
                            }
                            else if (String.Compare(c, 0, "PLATFORM=", 0, 9, StringComparison.OrdinalIgnoreCase) == 0)
                            {
                                _platform = c.Substring(9);
                            }
                        }
                    }
                    _wasMatch = true;

                    bool useCache = Environment.GetEnvironmentVariable("MSBUILDDISABLEASSEMBLYFOLDERSEXCACHE") == null;
                    string key = "ca22615d-aa83-444b-80b9-b32f3d5db097" + this.searchPathElement;
                    if (useCache && _buildEngine != null)
                    {
                        _assemblyFoldersCache = _buildEngine.GetRegisteredTaskObject(key, RegisteredTaskObjectLifetime.Build) as AssemblyFoldersExCache;
                    }

                    if (_assemblyFoldersCache == null)
                    {
                        AssemblyFoldersEx assemblyFolders = new AssemblyFoldersEx(_registryKeyRoot, _targetRuntimeVersion, _registryKeySuffix, _osVersion, _platform, _getRegistrySubKeyNames, _getRegistrySubKeyDefaultValue, this.targetProcessorArchitecture, _openBaseKey);
                        _assemblyFoldersCache = new AssemblyFoldersExCache(assemblyFolders, fileExists);
                        if (useCache && _buildEngine != null)
                        {
                            _buildEngine.RegisterTaskObject(key, _assemblyFoldersCache, RegisteredTaskObjectLifetime.Build, true /* dispose early ok*/);
                        }
                    }

                    fileExists = _assemblyFoldersCache.FileExists;
                }
            }
        }