code: public Date getUnsharedAt() {
          if(mBodyMap.containsKey(BoxItem.FIELD_SHARED_LINK)) {
              return  ((BoxSharedLink) mBodyMap.get(BoxItem.FIELD_SHARED_LINK)).getUnsharedDate();
          }
          return null;
      }
docs: Returns the date the link will be disabled at currently set in the request.
  
  @return  date the shared link will be disabled at, or null if not set.