code: def __init__(
      self,
      cfg,
      tokenizer,
      name,
      num_samples,
      max_seq_length,
      max_seq_length_dec,
      seed,
  ):
      super().__init__()
      self.name = name
      self.max_seq_length = max_seq_length
      self.max_seq_length_dec = max_seq_length_dec
      self.vocab_size = tokenizer.vocab_size
      self.length = num_samples
      self.seed = seed
  
imports: import collections
  import os
  import numpy
  import torch
  from nemo.collections.common.tokenizers import SentencePieceTokenizer, YouTokenToMeTokenizer
  from nemo.collections.nlp.data.language_modeling.megatron.dataset_utils import create_masked_lm_predictions, get_samples_mapping
  from nemo.collections.nlp.data.language_modeling.megatron.gpt_dataset import _build_index_mappings
  from nemo.core import Dataset
label_desc: Use image node_id 1 to create a new MockT5Dataset object from inherited base classes: Dataset with example: obj = MockT5Dataset(cfg, tokenizer, name, num_samples, max_seq_length, max_seq_length_dec, seed)