Starting with version 1.30.1 of clients/google-api-services-youtube/v3/VERSION/com/google/api/services/youtube/YouTube.java, the definition of the part field of the List class changed from private java.lang.String part to private java.util.List<java.lang.String> part, but the Javadoc documentation still describes part as "a comma-separated list" list of properties(this description happens in several places in YouTube.java).
I guess there are no more commas between properties, and now there's one String in the list per property instead? Is that correct?