*
* Properties:
* - #size: The size of the input element in characters.
+ * - #pattern: A string for the native HTML5 pattern attribute.
*
* Usage example:
* @code
* $form['phone'] = array(
* '#type' => 'tel',
* '#title' => $this->t('Phone'),
+ * '#pattern' => '[^\d]*',
* );
* @endcode
*