This closure receives as argument the value of the option after validating it

and before normalizing it when the option is being resolved.

Chaining option configurations

In many cases you may need to define multiple configurations for each option.

For example, suppose the ``Mailer`` class has an ``host`` option that is required

and a ``transport`` option which can be one of ``sendmail``, ``mail`` and ``smtp``.

You can improve the readability of the code avoiding to duplicate option name for

each configuration using the method

:method:`Symfony\\Component\\OptionsResolver\\OptionsResolver::define``::

..versionadded::5.1

The ``define()`` method was introduced in Symfony 5.1.

Performance Tweaks