code: def _save_html(basename, all_charts):
      """Save Altair chart as an HTML file."""
      output_path = basename + ".visual_report.html"
      image_download_filename = (
          os.path.basename(basename) + ".visual_report"
      )
      html_string = _altair_chart_to_html(
          altair_chart=all_charts,
          download_filename=image_download_filename,
      )
  
      with tf.io.gfile.GFile(output_path, "w") as writer:
          writer.write(html_string)
  
imports: import io
  import json
  import os
  import altair
  import numpy
  import pandas
  import tensorflow
label_desc: Use image node_id 15 for calling a global function with example usage: _save_html(basename, all_charts) without return types