code: def get_trainer(trainer_name: str):
      """Returns trainer given its name."""
      if trainer_name == "single_task_trainer":
          return single_task_trainer.train
      raise ValueError(f"Unsupported trainer: {trainer_name}.")
  
file_path: scenic/scenic/projects/unloc/main.py
imports: from absl import flags
  from clu import metric_writers
  import jax
  import jax.numpy
  import ml_collections
  from scenic import app
  from scenic.projects.unloc import model
  from scenic.projects.unloc import single_task_trainer
  from scenic.train_lib import train_utils
label_desc: Use image node_id 1 for calling a global function with example usage: get_trainer(trainer_name) and returns: single_task_trainer