public void InstallSnapshot(
            IEnumerable <DependencyManifestEntry> dependencies,
            string targetPath,
            PowerShell pwsh,
            DependencySnapshotInstallationMode installationMode,
            ILogger logger)
        {
            var installingPath = CreateInstallingSnapshot(targetPath);

            logger.Log(
                isUserOnlyLog: false,
                LogLevel.Trace,
                string.Format(
                    PowerShellWorkerStrings.InstallingFunctionAppRequiredModules,
                    installingPath,
                    installationMode));

            try
            {
                foreach (DependencyInfo module in GetExactVersionsOfDependencies(dependencies))
                {
                    InstallModule(module, installingPath, pwsh, logger);
                }

                _snapshotContentLogger.LogDependencySnapshotContent(installingPath, logger);

                switch (installationMode)
                {
                case DependencySnapshotInstallationMode.Optional:
                    // If the new snapshot turns out to be equivalent to the latest one,
                    // removing it helps us save storage space and avoid unnecessary worker restarts.
                    // It is ok to do that during background upgrade because the current
                    // worker already has a good enough snapshot, and nothing depends on
                    // the new snapshot yet.
                    PromoteToInstalledOrRemove(installingPath, targetPath, installationMode, logger);
                    break;

                case DependencySnapshotInstallationMode.Required:
                    // Even if the new snapshot turns out to be equivalent to the latest one,
                    // removing it would not be safe because the current worker already depends
                    // on it, as it has the path to this snapshot already added to PSModulePath.
                    // As opposed to the background upgrade case, this snapshot is *required* for
                    // this worker to run, even though it occupies some space (until the workers
                    // restart and the redundant snapshots are purged).
                    PromoteToInstalled(installingPath, targetPath, installationMode, logger);
                    break;

                default:
                    throw new ArgumentException($"Unexpected installation mode: {installationMode}", nameof(installationMode));
                }
            }
            catch (Exception e)
            {
                var message = string.Format(
                    PowerShellWorkerStrings.FailedToInstallDependenciesSnapshot,
                    targetPath,
                    installationMode);

                logger.Log(isUserOnlyLog: false, LogLevel.Warning, message, e);
                _storage.RemoveSnapshot(installingPath);
                throw;
            }
            finally
            {
                _moduleProvider.Cleanup(pwsh);
            }
        }
        public void InstallSnapshot(
            IEnumerable <DependencyManifestEntry> dependencies,
            string targetPath,
            PowerShell pwsh,
            ILogger logger)
        {
            logger.Log(isUserOnlyLog: false, LogLevel.Trace, PowerShellWorkerStrings.InstallingFunctionAppDependentModules);

            var installingPath = CreateInstallingSnapshot(targetPath);

            try
            {
                foreach (DependencyInfo module in GetExactVersionsOfDependencies(dependencies))
                {
                    logger.Log(isUserOnlyLog: false, LogLevel.Trace, string.Format(PowerShellWorkerStrings.StartedInstallingModule, module.Name, module.ExactVersion));

                    int tries = 1;

                    while (true)
                    {
                        try
                        {
                            _moduleProvider.SaveModule(pwsh, module.Name, module.ExactVersion, installingPath);

                            var message = string.Format(PowerShellWorkerStrings.ModuleHasBeenInstalled, module.Name, module.ExactVersion);
                            logger.Log(isUserOnlyLog: false, LogLevel.Trace, message);

                            break;
                        }
                        catch (Exception e)
                        {
                            string currentAttempt = GetCurrentAttemptMessage(tries);
                            var    errorMsg       = string.Format(PowerShellWorkerStrings.FailToInstallModule, module.Name, module.ExactVersion, currentAttempt, e.Message);
                            logger.Log(isUserOnlyLog: false, LogLevel.Error, errorMsg);

                            if (tries >= MaxNumberOfTries)
                            {
                                errorMsg = string.Format(PowerShellWorkerStrings.FailToInstallFuncAppDependencies, e.Message);
                                throw new DependencyInstallationException(errorMsg, e);
                            }
                        }

                        // Wait for 2^(tries-1) seconds between retries. In this case, it would be 1, 2, and 4 seconds, respectively.
                        var waitTimeSpan = TimeSpan.FromSeconds(Math.Pow(2, tries - 1));
                        Thread.Sleep(waitTimeSpan);

                        tries++;
                    }
                }

                _storage.PromoteInstallingSnapshotToInstalledAtomically(targetPath);
            }
            catch (Exception e)
            {
                var message = string.Format(PowerShellWorkerStrings.FailedToInstallDependenciesSnapshot, targetPath);
                logger.Log(isUserOnlyLog: false, LogLevel.Warning, message, e);
                _storage.RemoveSnapshot(installingPath);
                throw;
            }
            finally
            {
                _moduleProvider.Cleanup(pwsh);
            }
        }