Jose\KeyConverter\KeyConverter::loadKeyFromCertificateFile PHP Method

    public static function loadKeyFromCertificateFile($file)
    {
        Assertion::true(file_exists($file), sprintf('File "%s" does not exist.', $file));
        $content = file_get_contents($file);
        return self::loadKeyFromCertificate($content);
    }

 /**
  * {@inheritdoc}
  */
 public static function createFromCertificateFile($file, array $additional_values = [])
 {
     $values = KeyConverter::loadKeyFromCertificateFile($file);
     $values = array_merge($values, $additional_values);
     return new JWK($values);
 }