function getCMSFields()
 {
     $fields = parent::getCMSFields();
     $tf1 = new TagField('TestTagString', "Single column tags (try 'one', 'two', 'three', 'four')", 'TestTag');
     $fields->addFieldToTab('Root.Content.Main', $tf1);
     $tf2 = new TagField('TestTags', "Relation tags (try 'one', 'two', 'three', 'four')", null, 'TestTag');
     $fields->addFieldToTab('Root.Content.Main', $tf2);
     $tf3 = new TagField('FixedTags', "Fixed tags (try 'PHP', 'Ruby', 'Python')", null, 'TestTag');
     $tf3->setCustomTags(array('PHP', 'Ruby', 'Python'));
     $fields->addFieldToTab('Root.Content.Main', $tf3);
     return $fields;
 }