/**
  * @return string
  */
 function GetContentTypeName()
 {
     $contentTypeHeader = $this->Headers->GetHeaderDecodedValueByName(MIMEConst_ContentTypeLower);
     if ($contentTypeHeader) {
         $headerParameters =& new HeaderParameterCollection($contentTypeHeader);
         $param = $headerParameters->GetByName(MIMEConst_NameLower);
         if ($param) {
             return $param->Value;
         }
     }
     return '';
 }