code: public GetSingleConversationOptions filters(List<String> filters) {
          if(filters.size() == 1) { //Canvas API doesn't want the [] if it is only one value
              addSingleItem("filter", filters.get(0));
          } else {
              optionsMap.put("filter[]", filters);
          }
          return this;
      }
docs: Used when setting the "visible" field in the response. See the "List Conversations" docs for details
  @param filters Filter strings to be applied to the visibility of conversations
  @return this to continue building options