def METHOD_NAME(text, as_utf8):
  # type: (...) -> str
  """Escape a bytes string for use in an text protocol buffer.
  Args:
    text: A byte string to be escaped.
    as_utf8: Specifies if result may contain non-ASCII characters.
        In Python 3 this allows unescaped non-ASCII Unicode characters.
        In Python 2 the return value will be valid UTF-8 rather than only ASCII.
  Returns:
    Escaped string (str).
  """
  # Python's text.encode() 'string_escape' or 'unicode_escape' codecs do not
  # satisfy our needs; they encodes unprintable characters using two-digit hex
  # escapes whereas our C++ unescaping function allows hex escapes to be any
  # length.  So, "\0011".encode('string_escape') ends up being "\\x011", which
  # will be decoded in C++ as a single-character string with char code 0x11.
  text_is_unicode = isinstance(text, str)
  if as_utf8 and text_is_unicode:
    # We're already unicode, no processing beyond control char escapes.
    return text.translate(_cescape_chr_to_symbol_map)
  ord_ = ord if text_is_unicode else lambda x: x  # bytes iterate as ints.
  if as_utf8:
    return ''.join(_cescape_unicode_to_str[ord_(c)] for c in text)
  return ''.join(_cescape_byte_to_str[ord_(c)] for c in text)