docs: public AccumulateDescrBuilder<CEDescrBuilder<P, T>> accumulate() {
          // here we have to do a trick as a top level accumulate is just an accumulate
          // whose result pattern is Object[]
  
          // create a linked Object[] pattern and set it to query false
          PatternDescrBuilder<CEDescrBuilder<P,T>> pdb = pattern("Object[]").isQuery( false );
  
          // create the accumulate builder with this CE as its parent
          AccumulateDescrBuilder<CEDescrBuilder<P, T>> accumulate = new AccumulateDescrBuilderImpl<CEDescrBuilder<P, T>>(this);
  
          // set the accumulate descriptor as the source of that pattern descr
          pdb.getDescr().setSource( accumulate.getDescr() );
  
          // return the accumulate builder, that has the properly set parent
          return accumulate;
      }