Array
(
    [1885] => Array
        (
            [parent_category_id] => 1885
            [parent_category] => Array
                (
                    [id] => 1885
                    [slug] => business-finance
                    [name] => Business and Finance
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Macroeconomics
                            [slug] => macroeconomics
                            [id] => 1891
                        )

                    [1] => Array
                        (
                            [name] => Microeconomics
                            [slug] => microeconomics
                            [id] => 1892
                        )

                )

        )

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

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Calculus
                            [slug] => calculus
                            [id] => 1730
                        )

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

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

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

                    [4] => Array
                        (
                            [name] => Precalculus
                            [slug] => precalculus
                            [id] => 1728
                        )

                    [5] => Array
                        (
                            [name] => SAT Math
                            [slug] => sat-math
                            [id] => 1740
                        )

                )

        )

)