/**
  * Returns true if the passed HeaderPart is a Token instance and a space.
  * 
  * @param HeaderPart $part
  * @return bool
  */
 private function isSpaceToken(HeaderPart $part)
 {
     return $part instanceof Token && $part->isSpace();
 }
 /**
  * Checks if the passed part represents the beginning or end of an address
  * part (less than/greater than characters) and either appends the value of
  * the part to the passed $strValue, or sets up $strName
  * 
  * @param HeaderPart $part
  * @param string $strName
  * @param string $strValue
  */
 private function processSinglePart(HeaderPart $part, &$strName, &$strValue)
 {
     $pValue = $part->getValue();
     if ($part instanceof Token) {
         if ($pValue === '<') {
             $strName = $strValue;
             $strValue = '';
             return;
         } elseif ($pValue === '>') {
             return;
         }
     }
     $strValue .= $pValue;
 }