const GENERAL_CD_ENCRYPTED = 13;
/**
- * Private constructor
* @param string $fileName
* @param callable $callback
* @param array $options
* in the file to satisfy the request, an exception will be thrown.
*
* @param int $start The byte offset of the start of the block.
- * @param int $length The number of bytes to return. If omitted, the remainder
+ * @param int|null $length The number of bytes to return. If omitted, the remainder
* of the file will be returned.
*
* @return string