public void AddDatabases()
{
var migrationManager = new MigrationManager();
var databaseMock = new Mock <IMongoDatabase>();
Assert.Throws <ArgumentNullException>(() => migrationManager.AddDatabase(null, "general"));
Assert.Throws <ArgumentNullException>(() => migrationManager.AddDatabaseConnection(null, "general"));
Assert.Throws <ArgumentNullException>(() => migrationManager.AddDatabase(databaseMock.Object, null));
Assert.Throws <ArgumentNullException>(() => migrationManager.AddDatabase(databaseMock.Object, ""));
Assert.DoesNotThrow(() => migrationManager.AddDatabase(databaseMock.Object, "general"));
}