private function execVariables(array $options) {
    foreach ($options as $variable => $value) {
      if ($value === '[DELETE]') {
        variable_del($variable);
        drush_print(dt("'@var' was deleted.", ['@var' => $variable]));
      }
      else {
        variable_set($variable, $value);

        if (is_scalar($value)) {
          drush_print(dt("'@var' set to @val.", [
            '@var' => $variable,
            '@val' => $value,
          ]));
        }
        else {
          drush_print(dt("'@var' has been set.", ['@var' => $variable]));
        }
      }
    }
  }