def error(self, i: int=None) -> str:
        """
        Returns an error message
        """
        head = "[" + colors.red("error") + "]"
        if i is not None:
            head = str(i) + " " + head
        return head
def error ( self , i : int = None ) -> str : head = "[" + colors . red ( "error" ) + "]" if i is not None : head = str ( i ) + " " + head return head
Returns an error message