Array
(
    [1840] => Array
        (
            [parent_category_id] => 1840
            [parent_category] => Array
                (
                    [id] => 1840
                    [slug] => art-design
                    [name] => Art and Design
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Art History
                            [slug] => art-history
                            [id] => 1841
                        )

                )

        )

    [1760] => Array
        (
            [parent_category_id] => 1760
            [parent_category] => Array
                (
                    [id] => 1760
                    [slug] => english-reading
                    [name] => English and Reading
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Grammar
                            [slug] => grammar
                            [id] => 1761
                        )

                    [1] => Array
                        (
                            [name] => Literature
                            [slug] => literature
                            [id] => 1766
                        )

                    [2] => Array
                        (
                            [name] => Reading
                            [slug] => reading
                            [id] => 1763
                        )

                    [3] => Array
                        (
                            [name] => SAT Reading
                            [slug] => sat-reading
                            [id] => 1770
                        )

                )

        )

    [1772] => Array
        (
            [parent_category_id] => 1772
            [parent_category] => Array
                (
                    [id] => 1772
                    [slug] => history-social-studies
                    [name] => History and Social Studies
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => European History
                            [slug] => european-history
                            [id] => 1774
                        )

                )

        )

    [1699] => Array
        (
            [parent_category_id] => 1699
            [parent_category] => Array
                (
                    [id] => 1699
                    [slug] => languages
                    [name] => Languages
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => English
                            [slug] => english
                            [id] => 1704
                        )

                    [1] => Array
                        (
                            [name] => Russian
                            [slug] => russian
                            [id] => 1709
                        )

                )

        )

)