add a classes to buddypress activity page

function yoostart_member_type_body_class( $classes = array() ){
    if (bp_is_activity_component() ) {
        if ($member_types = bp_get_member_type( bp_displayed_user_id() ) ) {
            foreach ($member_types as $member_type) {
                $classes[] = sprintf( 'member-type-%s', esc_attr( $member_type ) );
            }
        }
    }
}
add_filter( 'bp_get_the_body_class', 'yoostart_member_type_body_class');