<?php
function getMostUsedTaxonomies($taxonomy, $fields = 'all', $orderBy = 'count', $orderDirection = 'desc', $limit = '30') {
    $transientName = 'mostUsedTaxonomies_'.$taxonomy.'_'.$fields.'_'.$orderBy.'_'.$orderDirection.'_'.$limit;
    $mainTechnologies = get_transient( $transientName );
    if ( $mainTechnologies === false ) {
        $params = array(
            'taxonomy' => $taxonomy,
            'hide_empty' => true,
            'orderby' => $orderBy,
            'order' => $orderDirection,
            'number' => $limit,
            'fields' => $fields
        );
        $mainTechnologies = get_terms($params);
        set_transient($transientName, $mainTechnologies, 60*60*24);
    }
    return $mainTechnologies;
}