validate (ActiveMerchant::Billing::Check)

    # File lib/active_merchant/billing/check.rb, line 30
          def validate
            [:name, :routing_number, :account_number].each do |attr|
              errors.add(attr, "cannot be empty") if self.send(attr).blank?
            end

            errors.add(:routing_number, "is invalid") unless valid_routing_number?

            errors.add(:account_holder_type, "must be personal or business") if
                !account_holder_type.blank? && !%w[business personal].include?(account_holder_type.to_s)

            errors.add(:account_type, "must be checking or savings") if
                !account_type.blank? && !%w[checking savings].include?(account_type.to_s)
          end