code: def load_dataset(self, split, **kwargs):
      split_map = {
          "train": self.mmtask.train_data,
          "valid": self.mmtask.val_data,
          "test": self.mmtask.test_data,
      }
      if split not in split_map:
          raise ValueError("unknown split type.")
      if split_map[split] is not None:
          self.datasets[split] = FairseqMMDataset(split_map[split])
  
file_path: fairseq/examples/MMPT/mmpt/tasks/fairseqmmtask.py
imports: import random
  from fairseq.tasks import LegacyFairseqTask, register_task
  from .task import Task
  from .retritask import RetriTask
  from ..datasets import FairseqMMDataset
  from ..None import utils
label_desc: Use image node_id 4 for calling the FairseqMMTask obj's underlying member method code with example usage: obj.load_dataset(split) without return types