Array
(
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        (
            [id_attribute_group] => 5
            [is_color_group] => 0
            [group_name] => Litres
            [public_group_name] => liters
            [id_attribute] => 157
            [attribute_name] => 750ml
            [attribute_color] => 
            [id_product_attribute] => 51330
            [quantity] => 1
            [price] => 0.000000
            [ecotax] => 0.000000
            [weight] => 0.100000
            [default_on] => 1
            [reference] => 026448
            [unit_price_impact] => 0.000000
            [minimal_quantity] => 1
            [available_date] => 0000-00-00
            [group_type] => select
        )

)
1

750ml

Array
(
    [5] => Array
        (
            [id_attribute_group] => 5
            [is_color_group] => 0
            [group_name] => Litres
            [public_group_name] => liters
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            [attribute_name] => 2.2lt
            [attribute_color] => 
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            [price] => 2.500000
            [ecotax] => 0.000000
            [weight] => 0.100000
            [default_on] => 
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            [unit_price_impact] => 0.000000
            [minimal_quantity] => 1
            [available_date] => 0000-00-00
            [group_type] => select
        )

)
1

2.2lt