/**
  * @see Filter::getSupportedTransformations()
  */
 function getSupportedTransformations()
 {
     $inputType = 'metadata::lib.pkp.classes.metadata.nlm.NlmNameSchema(*)';
     $outputType = 'primitive::string';
     $singleMode = array($inputType, $outputType);
     $multiMode = array($inputType . '[]', $outputType);
     return parent::getSupportedTransformations($singleMode, $multiMode);
 }