```ruby
class RequireBatchAndRecordedAtInLiveTimes < ActiveRecord::Migration
  def change
    change_column :live_times, :batch, :string, null: false
    change_column :live_times, :recorded_at, :datetime, null: false
  end
end
```

Fix live_times migration requiring batch and recorded_at to make it reversible.
user
```ruby
class RequireBatchAndRecordedAtInLiveTimes < ActiveRecord::Migration
  def up
    change_column_null :live_times, :batch, false
    change_column_null :live_times, :recorded_at, false
  end

  def down
    change_column_null :live_times, :batch, true
    change_column_null :live_times, :recorded_at, true
  end
end
```
assistant