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

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => ACT Math
                            [slug] => act-math
                            [id] => 1741
                        )

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

                    [2] => Array
                        (
                            [name] => Algebra 2
                            [slug] => algebra-2
                            [id] => 1726
                        )

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

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

                    [5] => Array
                        (
                            [name] => Linear Algebra
                            [slug] => linear-algebra
                            [id] => 1733
                        )

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

                )

        )

    [1903] => Array
        (
            [parent_category_id] => 1903
            [parent_category] => Array
                (
                    [id] => 1903
                    [slug] => special-needs-learning
                    [name] => Special Needs and Learning Support
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Special Needs
                            [slug] => special-needs
                            [id] => 1906
                        )

                    [1] => Array
                        (
                            [name] => Study Skills
                            [slug] => study-skills
                            [id] => 1910
                        )

                )

        )

)