function _storeExterncount($count)
    {
        $record = 0x0016;          // Record identifier
        $length = 0x0002;          // Number of bytes to follow

        $header = pack("vv", $record, $length);
        $data   = pack("v",  $count);
        $this->_prepend($header . $data);
    }
function _storeExterncount($count)
    {
        $record = 0x0016;          // Record identifier
        $length = 0x0002;          // Number of bytes to follow

        $header = pack("vv", $record, $length);
        $data   = pack("v",  $count);
        $this->_prepend($header . $data);
    }
function _storeExterncount ( $ count ) { $ record = 0x0016 ; // Record identifier
 $ length = 0x0002 ; // Number of bytes to follow
 $ header = pack ( "vv" , $ record , $ length ) ; $ data = pack ( "v" , $ count ) ; $ this -> _prepend ( $ header . $ data ) ; }
Write BIFF record EXTERNCOUNT to indicate the number of external sheet
references in a worksheet.

Excel only stores references to external sheets that are used in formulas.
For simplicity we store references to all the sheets in the workbook
regardless of whether they are used or not. This reduces the overall
complexity and eliminates the need for a two way dialogue between the formula
parser the worksheet objects.

@access private
@param integer $count The number of external sheet references in this worksheet
Write BIFF record EXTERNCOUNT to indicate the number of external sheet references in a worksheet .