How to use the pyglossary.text_utils.toStr function in pyglossary

def get_prefix(word, length):
	"""
	Return the prefix for the given word,
	of length length.

	:param word: the word string
	:type  word: unicode
	:param length: prefix length
	:type  length: int
	:rtype: unicode
	"""
	if not word:
		return None
	word = toStr(word)
	if "Z" < word[0] < "a":
		return "SPECIAL"
	return word[:length] ## return a unicode? FIXME

def rawDumpFileWriteText(self, text):  # FIXME
		text = toStr(text)
		if self.rawDumpFile:
			self.rawDumpFile.write(text)

def rawDumpFileWriteData(self, text):
		text = toStr(text)
		# the next function escapes too many chars, for example, it escapes äöü
		# self.rawDumpFile.write(text.encode("unicode_escape"))
		if self.rawDumpFile:
			self.rawDumpFile.write(text)

def samplesDumpFileWrite(self, text):
		text = toStr(text)
		if self.samplesDumpFile:
			offset = self.samplesDumpFile.tell()
			self.samplesDumpFile.write("\noffset = {0:#X}\n" % offset)
			self.samplesDumpFile.write(text+"\n")
		else:
			log.debug(text)

def msgLogFileWrite(self, text):
		text = toStr(text)
		if self.msgLogFile:
			offset = self.msgLogFile.tell()
			# print offset in the log file to facilitate navigating this
			# log in hex editor
			# intended usage:
			# the log file is opened in a text editor and hex editor
			# use text editor to read error messages, use hex editor to
			# inspect char codes offsets allows to quickly jump to the right
			# place of the file hex editor
			self.msgLogFile.write("\noffset = {0:#X}\n" % offset)
			self.msgLogFile.write(text+"\n")
		else:
			log.debug(text)

def processDefiStat(self, fields, b_defi, b_key):
		if fields.singleEncoding:
			self.findAndPrintCharSamples(
				fields.b_defi,
				"defi, key = %s" + b_key,
				fields.encoding,
			)
			if self.metadata2:
				self.metadata2.defiProcessedCount += 1
				if isASCII(toStr(fields.b_defi)):
					self.metadata2.defiAsciiCount += 1
				try:
					fields.b_defi.decode("utf8")
				except UnicodeError:
					pass
				else:
					self.metadata2.defiUtf8Count += 1
		if self.metadata2 and self.metadata2.isDefiASCII:
			if not isASCII(fields.u_defi):
				self.metadata2.isDefiASCII = False