code: def test_loss_build(self, filepath):
      logger.warning(f"Loading {filepath}")
      cfg = hydra_compose(
          [
              filepath,
              "config.DATA.TRAIN.DATA_SOURCES=[synthetic]",
              "config.DATA.TEST.DATA_SOURCES=[synthetic]",
          ]
      )
      _, config = convert_to_attrdict(cfg)
      task = SelfSupervisionTask.from_config(config)
      task.datasets, _ = task.build_datasets()
      try:
          self.assertTrue(
              task._build_loss(), f"failed to build loss: {filepath}"
          )
      except Exception as e:
          logger.error(f"failed to build loss: {filepath}")
          raise e
      return True
  
file_path: vissl/tests/test_losses_config.py
imports: import logging
  import unittest
  from collections import namedtuple
  from classy_vision.generic.distributed_util import set_cpu_device
  from utils import ROOT_LOSS_CONFIGS, SSLHydraConfig
  from vissl.trainer.train_task import SelfSupervisionTask
  from vissl.utils.hydra_config import convert_to_attrdict, hydra_compose
  from vissl.utils.test_utils import parameterized_parallel
label_desc: Use image node_id 1 for calling the TestRootConfigsLossesBuild obj's underlying member method code with example usage: obj.test_loss_build(filepath) and returns: True