docs: def to_utf8(text):
      """ Enforce UTF8 encoding.
      """
      # return empty/false stuff unaltered
      if not text:
          if isinstance(text, string_types):
              text = ""
          return text
  
      try:
          # Is it a unicode string, or pure ascii?
          return text.encode("utf8")
      except UnicodeDecodeError:
          try:
              # Is it a utf8 byte string?
              if text.startswith(codecs.BOM_UTF8):
                  text = text[len(codecs.BOM_UTF8):]
              return text.decode("utf8").encode("utf8")
          except UnicodeDecodeError:
              # Check BOM
              if text.startswith(codecs.BOM_UTF16_LE):
                  encoding = "utf-16le"
                  text = text[len(codecs.BOM_UTF16_LE):]
              elif text.startswith(codecs.BOM_UTF16_BE):
                  encoding = "utf-16be"
                  text = text[len(codecs.BOM_UTF16_BE):]
              else:
                  # Assume CP-1252
                  encoding = "cp1252"
  
              try:
                  return text.decode(encoding).encode("utf8")
              except UnicodeDecodeError as exc:
                  for line in text.splitlines():
                      try:
                          line.decode(encoding).encode("utf8")
                      except UnicodeDecodeError:
                          log.warn("Cannot transcode the following into UTF8 cause of %s: %r" % (exc, line))
                          break
                  return text