class_docstr: Task for joint training speech and text to text.
class_docstr_tok: ["Task","for","joint","training","speech","and","text","to","text","."]
code: def build_src_tokenizer(self, args):
      logger.info(
          f"src-pre-tokenizer: {self.data_cfg.src_pre_tokenizer}"
      )
      return encoders.build_tokenizer(
          Namespace(**self.data_cfg.src_pre_tokenizer)
      )
  
imports: import logging
  import os
  from argparse import Namespace
  from pathlib import Path
  import torch
  from fairseq.data import encoders, Dictionary, ResamplingDataset, TransformEosLangPairDataset, ConcatDataset
  from fairseq.data.iterators import GroupedEpochBatchIterator
  from fairseq.data.audio.multi_modality_dataset import MultiModalityDataset, LangPairMaskDataset, ModalityDatasetItem
  from fairseq.data.audio.speech_to_text_dataset import SpeechToTextDataset, SpeechToTextDatasetCreator
  from fairseq.data.audio.speech_to_text_joint_dataset import S2TJointDataConfig, SpeechToTextJointDatasetCreator
  from fairseq.tasks import register_task
  from fairseq.tasks.speech_to_text import SpeechToTextTask
  from fairseq.tasks.translation import load_langpair_dataset
label_desc: Use image node_id 6 for calling the SpeechTextJointToTextTask obj's underlying member method code with example usage: obj.build_src_tokenizer(args) and returns: encoders