public SocialActivityActor getActor() {
    return actor;
  }
Wrapper class for encoding social activity streams based on
<a href="https://www.w3.org/TR/activitystreams-core/">Activity Stream 2.0</a>

<p>The wrapper is needed to allow DTP to page through large collections of items. DTP doesn't
know how to parse SocialActivityModel, only extensions that process social data will understand
this data, so it needs to by split up to allow DTP to efficiently process it.
portability-types-common/src/main/java/org/datatransferproject/types/common/models/social/SocialActivityContainerResource.java