code: def is_tone(char, strict=True):
  	
  	if char in chart.tones:
  		return True
  
  	if not strict:
  		return 0xA700 <= ord(char) <= 0xA71F
  
  	return False
docs: Check whether the character is a tone or word accent symbol. In strict mode
  	return True only for the symbols listed in the last group of the chart. If
  	strict=False, also accept symbols that belong to the Modifier Tone Letters
  	Unicode block [1].
  
  	[1]: http://www.unicode.org/charts/PDF/UA700.pdf