Array
(
    [1723] => Array
        (
            [parent_category_id] => 1723
            [parent_category] => Array
                (
                    [id] => 1723
                    [slug] => math
                    [name] => Math
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Algebra 1
                            [slug] => algebra-1
                            [id] => 1725
                        )

                    [1] => Array
                        (
                            [name] => Elementary Math
                            [slug] => elementary-math
                            [id] => 1743
                        )

                    [2] => Array
                        (
                            [name] => Geometry
                            [slug] => geometry
                            [id] => 1727
                        )

                    [3] => Array
                        (
                            [name] => Prealgebra
                            [slug] => prealgebra
                            [id] => 1724
                        )

                )

        )

    [1915] => Array
        (
            [parent_category_id] => 1915
            [parent_category] => Array
                (
                    [id] => 1915
                    [slug] => miscellaneous
                    [name] => Miscellaneous / Other
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Fitness
                            [slug] => fitness
                            [id] => 1917
                        )

                )

        )

)