Augment write routine to keep track of current line

def write(self, *data):
        """Augment write routine to keep track of current line"""
        for l in data:
            ## print("XXX write: '%s'" % l)
            for i in str(l):
                if i == '\n':
                    self.current_line_number += 1
                    pass
                pass
            pass
        return super(LineMapWalker, self).write(*data)