Form builder for form_state_values_clean() test.
function form_test_form_state_values_clean_form($form, &$form_state) {
// Build an example form containing multiple submit and button elements; not
// only on the top-level.
$form = array(
'#tree' => TRUE,
);
$form['foo'] = array(
'#type' => 'submit',
'#value' => t('Submit'),
);
$form['bar'] = array(
'#type' => 'submit',
'#value' => t('Submit'),
);
$form['beer'] = array(
'#type' => 'value',
'#value' => 1000,
);
$form['baz']['foo'] = array(
'#type' => 'button',
'#value' => t('Submit'),
);
$form['baz']['baz'] = array(
'#type' => 'submit',
'#value' => t('Submit'),
);
$form['baz']['beer'] = array(
'#type' => 'value',
'#value' => 2000,
);
return $form;
}