/**
  * get lead filter
  *
  * @return Crm_Model_LeadFilter
  */
 protected function _getFilter($container = 'single')
 {
     $filterData = array(array('field' => 'query', 'operator' => 'contains', 'value' => 'PHPUnit'));
     $filterData[] = $container == 'single' ? array('field' => 'container_id', 'operator' => 'equals', 'value' => $this->_testContainer->id) : array('field' => 'container_id', 'operator' => 'specialNode', 'value' => $container);
     $filter = new Crm_Model_LeadFilter($filterData);
     $filter->createFilter('showClosed', 'equals', TRUE);
     return $filter;
 }