phone_number.rb in twilio-ruby-5.0.0.rc25

- old
+ new

@@ -24,11 +24,14 @@
           end
 
           ##
           # Access the countries
           # @param [String] iso_country The iso_country
-          # @return [CountryList] CountryList
+          # @return [CountryList] if a(n) CountryList object was created.
+          # @return [CountryContext] if a(n) CountryContext object was created.
           def countries(iso_country=:unset)
+            raise ArgumentError, 'iso_country cannot be nil' if iso_country.nil?
+
             if iso_country != :unset
               return CountryContext.new(
                   @version,
                   iso_country,
               )
\ No newline at end of file