**type**: ``string`` or ``Boolean``

.. versionadded:: 2.3

Since Symfony 2.3, empty values are also supported if the ``expanded``

option is set to true.

This option determines whether or not a special "empty" option (e.g. "Choose an option")

will appear at the top of a select widget. This option only applies if the

the``multiple`` option is set to false.

``multiple`` option is set to false.

* Add an empty value with "Choose an option" as the text::