The code follows the Drupal coding standards:
https://www.drupal.org/coding-standards

Style compliance can be checked using the Coder Sniffer extension to the PEAR
PHP_CodeSniffer project, for instructions about how to install Coder Sniffer
see https://www.drupal.org/node/1419988

Use this command to check the style:

  $ phpcs --standard=Drupal .