code: def add(self, lines, message):
  		
  		error = Error(message)
  
  		if error not in self.errors:
  			self.errors[error] = []
  
  		self.errors[error].extend(lines)
docs: Adds a lint issue to the report. The first arg should be [] of lines on
  		which the issue is present. The second arg should be the error message.