# File lib/braintree/client_token.rb, line 15
    def self._validate_options(options)
      [:make_default, :fail_on_duplicate_payment_method, :verify_card].each do |credit_card_option|
        if options[credit_card_option]
          raise ArgumentError.new("cannot specify #{credit_card_option} without a customer_id") unless options[:customer_id]
        end
      end
    end