public MigrationsOperations(
            [NotNull] ILoggerProvider loggerProvider,
            [NotNull] string assemblyName,
            [NotNull] string startupAssemblyName,
            [NotNull] string projectDir,
            [NotNull] string rootNamespace,
            [CanBeNull] IServiceProvider dnxServices = null)
        {
            Check.NotNull(loggerProvider, nameof(loggerProvider));
            Check.NotEmpty(assemblyName, nameof(assemblyName));
            Check.NotEmpty(startupAssemblyName, nameof(startupAssemblyName));
            Check.NotNull(projectDir, nameof(projectDir));
            Check.NotNull(rootNamespace, nameof(rootNamespace));

            var loggerFactory = new LoggerFactory();
            loggerFactory.AddProvider(loggerProvider);

            _loggerProvider = loggerProvider;
            _logger = new LazyRef<ILogger>(() => loggerFactory.CreateCommandsLogger());
            _projectDir = projectDir;
            _rootNamespace = rootNamespace;
            _servicesBuilder = new DesignTimeServicesBuilder(dnxServices);
            _contextOperations = new DbContextOperations(
                loggerProvider,
                assemblyName,
                startupAssemblyName,
                dnxServices);
        }
        public DatabaseOperations(
            [NotNull] ILoggerProvider loggerProvider,
            [NotNull] string assemblyName,
            [NotNull] string startupAssemblyName,
            [CanBeNull] string environment,
            [NotNull] string projectDir,
            [NotNull] string rootNamespace)
        {
            Check.NotNull(loggerProvider, nameof(loggerProvider));
            Check.NotEmpty(assemblyName, nameof(assemblyName));
            Check.NotEmpty(startupAssemblyName, nameof(startupAssemblyName));
            Check.NotNull(projectDir, nameof(projectDir));
            Check.NotNull(rootNamespace, nameof(rootNamespace));

            _loggerProvider = loggerProvider;
            _projectDir = projectDir;
            _rootNamespace = rootNamespace;

            var startup = new StartupInvoker(startupAssemblyName, environment);
            _servicesBuilder = new DesignTimeServicesBuilder(startup);
        }