code: def maybe_get_metric_loss(self, embeddings, labels, indices_tuple):
      if self.loss_weights.get("metric_loss", 0) > 0:
          return self.loss_funcs["metric_loss"](
              embeddings, labels, indices_tuple
          )
      return 0
  
imports: from .base_trainer import BaseTrainer
label_desc: Use image node_id 2 for calling the MetricLossOnly obj's underlying member method code with example usage: obj.maybe_get_metric_loss(embeddings, labels, indices_tuple) and returns: int, self