`TextInput` `distinct` v3 equivalent in v2?

In v3 i do:

TextInput::make('name')
    ->required()
    ->distinct()

TextInput::make('name')
    ->required()
    ->distinct()

TextInput::make('name')
    ->required()
    ->distinct()

TextInput::make('name')
    ->required()
    ->distinct()

Now i have to do it also in a v2 project, but idk how to. which would be the equivalent?

TextInput::make('name')
    ->required()
    // ->distinct() (method doesn't exist in v2)

TextInput::make('name')
    ->required()
    // ->distinct() (method doesn't exist in v2)

TextInput::make('name')
    ->required()
    // ->distinct() (method doesn't exist in v2)

TextInput::make('name')
    ->required()
    // ->distinct() (method doesn't exist in v2)