src/Message/Stream/AbstractStream.php
public function isSeekable()
    {
        $seekable = false;
        if ($this->stream) {
            $meta = stream_get_meta_data($this->stream);
            $seekable = $meta['seekable'];
        }
        return $seekable;
    }
public function isSeekable()
    {
        $seekable = false;
        if ($this->stream) {
            $meta = stream_get_meta_data($this->stream);
            $seekable = $meta['seekable'];
        }
        return $seekable;
    }
Returns whether or not the stream is seekable.

@return bool