src/Stream.php
public function getMetadata($key = null)
    {
        $metas = stream_get_meta_data($this->fp);

        if (!is_null($key)) {
            if (isset($metas[$key])) {
                return $metas[$key];
            } else {
                return null;
            }
        } else {
            return $metas;
        }
    }
public function getMetadata($key = null)
    {
        $metas = stream_get_meta_data($this->fp);

        if (!is_null($key)) {
            if (isset($metas[$key])) {
                return $metas[$key];
            } else {
                return null;
            }
        } else {
            return $metas;
        }
    }
Get stream metadata as an associative array or retrieve a specific key.

The keys returned are identical to the keys returned from PHP's
stream_get_meta_data() function.

@link http://php.net/manual/en/function.stream-get-meta-data.php

@param string $key Specific metadata to retrieve.

@return array|mixed|null Returns an associative array if no key is
provided. Returns a specific key value if a key is provided and the
value is found, or null if the key is not found.