code: func (m *Migrate) RollbackLast() error {
  	if len(m.migrations) == 0 {
  		return ErrNoMigrationDefined
  	}
  
  	lastRunnedMigration, err := m.getLastRunnedMigration()
  	if err != nil {
  		return err
  	}
  
  	if err := m.RollbackMigration(lastRunnedMigration); err != nil {
  		return err
  	}
  	return nil
  }
docs: // RollbackLast undo the last migration