code: def normalise(self, string, line_num):
  		
  		stripped = string.strip()
  		if stripped != string:
  			self.strip_errors.append(line_num)
  
  		nfc_pos = [index
  					for index, char in enumerate(stripped)
  					if char in self.nfc_chars]
  
  		parts = []
  		start_pos = 0
  
  		for pos in nfc_pos:
  			if pos > 0:
  				parts.append(self.norm_f(stripped[start_pos:pos]))
  
  			parts.append(stripped[pos])
  			start_pos = pos + 1
  
  		if start_pos < len(stripped):
  			parts.append(self.norm_f(stripped[start_pos:]))
  
  		norm = ''.join(parts)
  
  		if norm != stripped:
  			self.norm_errors.append(line_num)
  
  		return norm
docs: Strips the whitespace and applies Unicode normalisation to the given
  		string. The second arg is used as an ID of the string when reporting
  		its lint errors (if such).