Swift_InputByteStream::write PHP Method

    public function write($bytes);

 /**
  * Encode stream $in to stream $out.
  *
  * @param Swift_OutputByteStream $os
  * @param Swift_InputByteStream  $is
  * @param int                    $firstLineOffset
  * @param int                    $maxLineLength,  optional, 0 indicates the default of 76 bytes
  */
 public function encodeByteStream(Swift_OutputByteStream $os, Swift_InputByteStream $is, $firstLineOffset = 0, $maxLineLength = 0)
 {
     if (0 >= $maxLineLength || 76 < $maxLineLength) {
         $maxLineLength = 76;
     }
     $remainder = 0;
     while (false !== ($bytes = $os->read(8190))) {
         $encoded = base64_encode($bytes);
         $encodedTransformed = '';
         $thisMaxLineLength = $maxLineLength - $remainder - $firstLineOffset;
         while ($thisMaxLineLength < strlen($encoded)) {
             $encodedTransformed .= substr($encoded, 0, $thisMaxLineLength) . "\r\n";
             $firstLineOffset = 0;
             $encoded = substr($encoded, $thisMaxLineLength);
             $thisMaxLineLength = $maxLineLength;
             $remainder = 0;
         }
         if (0 < ($remainingLength = strlen($encoded))) {
             $remainder += $remainingLength;
             $encodedTransformed .= $encoded;
             $encoded = null;
         }
         $is->write($encodedTransformed);
     }
 }