$preferences
$preferences : array
addExtension(string $extension) : \FirefoxProfile
| string | $extension | The path to the xpi extension. |
setPreference(string $key, string|boolean|integer $value) : \FirefoxProfile
| string | $key | |
| string|boolean|integer | $value |
extractTo(string $xpi, $target_dir) : \FirefoxProfile
| string | $xpi | The path to the .xpi extension. |
| $target_dir |