code: public <C> DbxDeltaC<C> getDeltaC(Collector<DbxDeltaC.Entry<DbxEntry>, C> collector, /*@Nullable*/String cursor,
                                        boolean includeMediaInfo)
          throws DbxException
      {
          return _getDeltaC(collector, cursor, null, includeMediaInfo);
      }
docs: A more generic version of {@link #getDelta}.  You provide a <em>collector</em>,
  which lets you process the delta entries as they arrive over the network.