+ * @global wpdb $wpdb WordPress database object for queries.
+ *
+ * @param array|string $args {
+ * Optional. Array or string of arguments to generate a drop-down of users.
+ * {@see WP_User_Query::prepare_query() for additional available arguments.
+ *
+ * @type string $show_option_all Text to show as the drop-down default (all).
+ * Default empty.
+ * @type string $show_option_none Text to show as the drop-down default when no
+ * users were found. Default empty.
+ * @type int|string $option_none_value Value to use for $show_option_non when no users
+ * were found. Default -1.
+ * @type string $hide_if_only_one_author Whether to skip generating the drop-down
+ * if only one user was found. Default empty.
+ * @type string $orderby Field to order found users by. Accepts user fields.
+ * Default 'display_name'.
+ * @type string $order Whether to order users in ascending or descending
+ * order. Accepts 'ASC' (ascending) or 'DESC' (descending).
+ * Default 'ASC'.
+ * @type array|string $include Array or comma-separated list of user IDs to include.
+ * Default empty.
+ * @type array|string $exclude Array or comma-separated list of user IDs to exclude.
+ * Default empty.
+ * @type bool|int $multi Whether to skip the ID attribute on the 'select' element.
+ * Accepts 1|true or 0|false. Default 0|false.
+ * @type string $show User table column to display. If the selected item is empty
+ * then the 'user_login' will be displayed in parentheses.
+ * Accepts user fields. Default 'display_name'.
+ * @type int|bool $echo Whether to echo or return the drop-down. Accepts 1|true (echo)
+ * or 0|false (return). Default 1|true.
+ * @type int $selected Which user ID should be selected. Default 0.
+ * @type bool $include_selected Whether to always include the selected user ID in the drop-
+ * down. Default false.
+ * @type string $name Name attribute of select element. Default 'user'.
+ * @type string $id ID attribute of the select element. Default is the value of $name.
+ * @type string $class Class attribute of the select element. Default empty.
+ * @type int $blog_id ID of blog (Multisite only). Default is ID of the current blog.
+ * @type string $who Which type of users to query. Accepts only an empty string or
+ * 'authors'. Default empty.
+ * }