code: def markdowns_to_safe_html(markdown_strings, combine):
      """Convert multiple Markdown documents to one safe HTML document.
  
      One could also achieve this by calling `markdown_to_safe_html`
      multiple times and combining the results. Compared to that approach,
      this function may be faster, because HTML sanitization (which can be
      expensive) is performed only once rather than once per input. It may
      also be less precise: if one of the input documents has unsafe HTML
      that is sanitized away, that sanitization might affect other
      documents, even if those documents are safe.
  
      Args:
        markdown_strings: List of Markdown source strings to convert, as
          Unicode strings or UTF-8--encoded bytestrings. Markdown tables
          are supported.
        combine: Callback function that takes a list of unsafe HTML
          strings of the same shape as `markdown_strings` and combines
          them into a single unsafe HTML string, which will be sanitized
          and returned.
  
      Returns:
        A string containing safe HTML.
      """
      unsafe_htmls = []
      total_null_bytes = 0
  
      for source in markdown_strings:
          # Convert to utf-8 whenever we have a binary input.
          if isinstance(source, bytes):
              source_decoded = source.decode("utf-8")
              # Remove null bytes and warn if there were any, since it probably means
              # we were given a bad encoding.
              source = source_decoded.replace("\x00", "")
              total_null_bytes += len(source_decoded) - len(source)
          unsafe_html = _MARKDOWN_STORE.markdown.convert(source)
          unsafe_htmls.append(unsafe_html)
  
      unsafe_combined = combine(unsafe_htmls)
      sanitized_combined = _CLEANER_STORE.cleaner.clean(unsafe_combined)
  
      warning = ""
      if total_null_bytes:
          warning = (
              "<!-- WARNING: discarded %d null bytes in markdown string "
              "after UTF-8 decoding -->\n"
          ) % total_null_bytes
  
      return warning + sanitized_combined
  
imports: import threading
  from bleach.sanitizer import Cleaner
  import markdown
  from tensorboard import context
  from tensorboard.backend import experiment_id
  from tensorboard.util import tb_logging
label_desc: Use image node_id 3 for calling a global function with example usage: markdowns_to_safe_html(markdown_strings, combine) and returns: unknown