code: public function _getPpsWk()
      {
          $ret = str_pad($this->Name, 64, "\x00");
  
          $ret .= pack('v', strlen($this->Name) + 2)  // 66
              . pack('c', $this->Type)              // 67
              . pack('c', 0x00) //UK                // 68
              . pack('V', $this->PrevPps) //Prev    // 72
              . pack('V', $this->NextPps) //Next    // 76
              . pack('V', $this->DirPps)  //Dir     // 80
              . "\x00\x09\x02\x00"                  // 84
              . "\x00\x00\x00\x00"                  // 88
              . "\xc0\x00\x00\x00"                  // 92
              . "\x00\x00\x00\x46"                  // 96 // Seems to be ok only for Root
              . "\x00\x00\x00\x00"                  // 100
              . OLE::localDateToOLE($this->Time1st)          // 108
              . OLE::localDateToOLE($this->Time2nd)          // 116
              . pack('V', isset($this->startBlock) ? $this->startBlock : 0)  // 120
              . pack('V', $this->Size)               // 124
              . pack('V', 0); // 128
          return $ret;
      }
docs: Returns a string with the PPS's WK (What is a WK?).
  
  @return string The binary string