docs: @Override
      public void setupSearchState(Pair<Gradient, Double> pair) {
          INDArray gradient = pair.getFirst().gradient(conf.variables());
          INDArray params = model.params().dup(); //Need dup here: params returns an array that isn't a copy (hence changes to this are problematic for line search methods)
          searchState.put(GRADIENT_KEY, gradient);
          searchState.put(SCORE_KEY, pair.getSecond());
          searchState.put(PARAMS_KEY, params);
      }