code: def read_timings() -> typing.Set[MatmulSize]:
      """Find timings already existing in the file."""
      out: typing.Set[MatmulSize] = set()
      with open(_OUTPUT_FILE.value) as f:
          reader = csv.reader(f)
          for row in reader:
              if row[0].isdigit():
                  # M, N, K + quantized_lhs
                  out.add(MatmulSize(*map(int, row[:4])))
      return out
  
imports: import concurrent.futures
  import csv
  import itertools
  import logging
  import os
  import random
  import sys
  import time
  import typing
  from absl import app
  from absl import flags
  from matmul_lib import benchmark_matmul
  from matmul_lib import generate_tiling_configs
  from matmul_lib import MatmulSize
  from matmul_lib import MatmulTiming
  from matmul_lib import parse_int_list
  from matmul_lib import parse_layout_list
  from matmul_lib import QuantizedInputType
  import numpy
  import torch
  import tqdm
  from tqdm.contrib.logging import logging_redirect_tqdm
label_desc: Use image node_id 1 for calling a global function with example usage: read_timings() and returns: out