* Properties:
* - #default_value: An RFC-compliant email address.
* - #size: The size of the input element in characters.
+ * - #pattern: A string for the native HTML5 pattern attribute.
*
* Example usage:
* @code
* $form['email'] = array(
* '#type' => 'email',
* '#title' => $this->t('Email'),
+ * '#pattern' => '*@example.com',
* );
* @end
*