class_docstr: Span masked language modeling task. (ie. T5)
code: def __init__(self, cfg, dictionary):
      super().__init__(cfg)
      self.dictionary = dictionary
  
imports: import logging
  import os
  from dataclasses import dataclass, field
  from typing import Optional
  import numpy
  from omegaconf import II, MISSING
  from fairseq import utils
  from fairseq.data import AppendTokenDataset, Dictionary, IdDataset, NestedDictionaryDataset, NumelDataset, PadDataset, PrependTokenDataset, StripTokenDataset, TokenBlockDataset, data_utils
  from fairseq.data.shorten_dataset import maybe_shorten_dataset
  from fairseq.data.span_mask_tokens_dataset import SpanMaskedTokensDataset
  from fairseq.dataclass import ChoiceEnum, FairseqDataclass
  from fairseq.tasks import FairseqTask, register_task
  from ..data.indexed_dataset import get_available_dataset_impl
label_desc: Use image node_id 1 to create a new SpanMaskedLMTask object from inherited base classes: FairseqTask with example: obj = SpanMaskedLMTask(cfg, dictionary)