Storage/src/StreamWrapper.php
public function stream_seek($offset, $whence = SEEK_SET)
    {
        if ($this->stream->isSeekable()) {
            $this->stream->seek($offset, $whence);
            return true;
        }
        return false;
    }
public function stream_seek($offset, $whence = SEEK_SET)
    {
        if ($this->stream->isSeekable()) {
            $this->stream->seek($offset, $whence);
            return true;
        }
        return false;
    }
public function stream_seek ( $ offset , $ whence = SEEK_SET ) { if ( $ this -> stream -> isSeekable ( ) ) { $ this -> stream -> seek ( $ offset , $ whence ) ; return true ; } return false ; }
Callback handler for trying to seek to a certain location in the stream.

@param int $offset The stream offset to seek to
@param int $whence Flag for what the offset is relative to. See:
http://php.net/manual/en/streamwrapper.stream-seek.php
@return bool
Callback handler for trying to seek to a certain location in the stream .