code: def _parse_out_timestamps(raw_texts, day_str):
      """Parsing timestamps from IRC chat messages.
  
      Similar logic is implemented here.
      https://github.com/jkkummerfeld/irc-disentanglement/blob/master/src/disentangle.py#L174
  
      Args:
        raw_texts: list of raw chat messages.
        day_str: formatted date string.
  
      Returns:
        texts: list of texts without timestamps.
        timestamps: list of formatted timestamps
      """
      prev_hours = 0
      timestamps, texts = [], []
      for raw_text in raw_texts:
          if raw_text.startswith(
              "["
          ):  # Regular messsages e.g. "[04:13]<xxx>: Hi!"
              hours = int(raw_text[1:3])
              mins = int(raw_text[4:6])
  
              # 12h format -> 24h format
              if (
                  hours < prev_hours
              ):  # All messages belong to the same day and are
                  hours += 12  # chronologically ordered, but AM/PM info is absent
              prev_hours = hours
  
              timestamps.append(
                  "{}_{:02}_{:02}".format(day_str, hours, mins)
              )
              raw_text = raw_text[7:]
          else:  # System messages e.g. "=== xxx has joned #ubuntu"
              timestamps.append("")
  
          texts.append(raw_text)
  
      return texts, timestamps
  
file_path: datasets/tensorflow_datasets/datasets/irc_disentanglement/irc_disentanglement_dataset_builder.py
imports: import collections
  import os
  from typing import List
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
  import tensorflow_datasets.public_api
label_desc: Use image node_id 4 for calling a global function with example usage: _parse_out_timestamps(raw_texts, day_str) and returns: texts,  timestamps