docs: boolean removeEntry(Object entry) {
          if (multiple == null) {
              if (entry.equals(single)) {
                  single = null;
                  return true;
              }
          } else {
              multiple.remove(entry);
              if (single.equals(entry)) {
                  single = multiple.peekLast();
              }
              if (multiple.size() == 1) {
                  multiple = null;
              }
          }
          return false;
      }