REST api does not have any specified behavior for returning issue fields that are empty

Recently, I wrote a ruby script to pull information for a few issues from JIRA using the new REST api. One of the issues does not contain a description. The response for this description has the value "java.lang.string." I also looked through the documentation to see what type of response I should be getting in the case of a field that has no data and was unable to find any information. (Perhaps I did not look at the right page.)

I'm attaching the script I used.