* Sanitizes every member of an array at every level with
		 * sanitize_text_field()
		 *
		 * @param  array $arr
		 * @return array
		 */
		protected function sanitize_array( $arr ) {
			foreach ( $arr as $key => $value ) {
				if ( is_array( $value ) ) {
					$arr[ $key ] = $this->sanitize_array( $value );