code: def _select_indices(self, y_pred, y_true):
      if self.pred_index is not None:
          y_pred = y_pred[self.pred_index]
      if self.true_index is not None:
          y_true = y_true[self.true_index]
      return y_pred, y_true
  
file_path: poutyne/poutyne/framework/metrics/metric_argument_indexing.py
imports: from poutyne.framework.metrics.base import Metric
  from poutyne.framework.metrics.decomposable import convert_decomposable_metric_to_object
  from poutyne.framework.metrics.metrics_registering import get_metric
  from poutyne.framework.metrics.utils import get_names_of_metric
label_desc: Use image node_id 2 for calling the IndexedArgumentMetric obj's underlying member method code with example usage: obj._select_indices(y_pred, y_true) and returns: y_pred,  y_true