code: def WriteHistogramSeries(writer, tag, mu_sigma_tuples, n=20):
      """Write a sequence of normally distributed histograms to writer."""
      step = 0
      wall_time = _start_time
      for [mean, stddev] in mu_sigma_tuples:
          data = [random.normalvariate(mean, stddev) for _ in range(n)]
          histo = _MakeHistogram(data)
          summary = tf.Summary(
              value=[tf.Summary.Value(tag=tag, histo=histo)]
          )
          event = tf.Event(
              wall_time=wall_time, step=step, summary=summary
          )
          writer.add_event(event)
          step += 10
          wall_time += 100
  
file_path: tensorboard/tensorboard/scripts/generate_testdata.py
imports: import bisect
  import math
  import os
  import os.path
  import random
  import shutil
  from absl import app
  from absl import flags
  import numpy
  import tensorflow
label_desc: Use image node_id 4 for calling a global function with example usage: WriteHistogramSeries(writer, tag, mu_sigma_tuples, n) without return types