How to enable the filter plugin option in Yii ECHMultiSelect widget?

Question

I have the following code that produces a jquery ech multiselect menu widget in Yii. (Eric Hynds multiselect). Unfortunately filter => true doesn't seem to be enabling the filter.

How do I enable the filter for this? Seems like the filter true switch should do it.

Current code:

$this->widget('ext.echMultiSelect.EchMultiSelect', array(
 'model' => $model,
 'dropDownAttribute' => 'isolates',     
 'data' => $data,
 'dropDownHtmlOptions'=> array(
      'style'=>'',
      'id'=>'isolates_select'
 ),
 'options'=> array(
      'header'=> false,
      'height'=>175,
      'minWidth'=>350,
      'position'=>array('my'=>'left top', 'at'=>'left top'),
      'selectedText' =>Yii::t('application','# selected'),
      'selectedList'=>1,
      'show'=>'',
      'hide'=>'',
      'autoOpen'=>false,
      'noneSelectedText'=>'-- select --',
      'multiple'=>true,
      'classes'=>'',
      'filter'=>true,
 ),  
 'filterOptions'=> array(
      'width'=>150,
 ),
));

Answer 1

Figured it out. Header also has to be set to true.

 'header'=> true,