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

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

                )

        )

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

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Trumpet
                            [slug] => trumpet
                            [id] => 1791
                        )

                )

        )

    [1785] => Array
        (
            [parent_category_id] => 1785
            [parent_category] => Array
                (
                    [id] => 1785
                    [slug] => music
                    [name] => Music
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Ear Training
                            [slug] => ear-training
                            [id] => 1796
                        )

                    [1] => Array
                        (
                            [name] => General Music
                            [slug] => general-music
                            [id] => 1786
                        )

                    [2] => Array
                        (
                            [name] => Music Theory
                            [slug] => music-theory
                            [id] => 1787
                        )

                    [3] => Array
                        (
                            [name] => Piano
                            [slug] => piano
                            [id] => 1789
                        )

                    [4] => Array
                        (
                            [name] => Trombone
                            [slug] => trombone
                            [id] => 1793
                        )

                    [5] => Array
                        (
                            [name] => Violin
                            [slug] => violin
                            [id] => 1792
                        )

                )

        )

)