def acts_as_google_user *modules
      # assign devise modules to module variable
      if modules.empty?
        self.devise_modules_to_include = [:omniauthable]
      else
        # restrict modules given to devise
        self.devise_modules_to_include = (modules + [:omniauthable] - FORBIDDEN_MODULES) & ALLOWED_MODULES
      end
      # include model methods
      include ActsAsGoogleUser::Model
    end
def acts_as_google_user *modules
      # assign devise modules to module variable
      if modules.empty?
        self.devise_modules_to_include = [:omniauthable]
      else
        # restrict modules given to devise
        self.devise_modules_to_include = (modules + [:omniauthable] - FORBIDDEN_MODULES) & ALLOWED_MODULES
      end
      # include model methods
      include ActsAsGoogleUser::Model
    end
Configure a model to be used with devise and google authentication
 @param [Array] modules a list of symbols used with a devise call