code: def _build_combined_description(descriptions, description_to_runs):
      """Creates a single description from a set of descriptions.
  
      Descriptions may be composites when a single tag has different descriptions
      across multiple runs.
  
      Args:
          descriptions: A list of description strings.
          description_to_runs: A map from description strings to a set of run
              strings.
  
      Returns:
          The combined description string.
      """
      prefixed_descriptions = []
      for description in descriptions:
          runs = sorted(description_to_runs[description])
          run_or_runs = "runs" if len(runs) > 1 else "run"
          run_header = "## For " + run_or_runs + ": " + ", ".join(runs)
          description_html = run_header + "\n" + description
          prefixed_descriptions.append(description_html)
  
      header = "# Multiple descriptions\n"
      return header + "\n".join(prefixed_descriptions)
  
imports: import collections
  import imghdr
  import json
  from werkzeug import wrappers
  from tensorboard import errors
  from tensorboard import plugin_util
  from tensorboard.backend import http_util
  from tensorboard.data import provider
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.histogram import metadata
  from tensorboard.plugins.image import metadata
  from tensorboard.plugins.metrics import metadata
  from tensorboard.plugins.scalar import metadata
label_desc: Use image node_id 2 for calling a global function with example usage: _build_combined_description(descriptions, description_to_runs) and returns: unknown