<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def warning(self, node, reason):
 """Used for warning the user about possible uncertainty in the translation. First argument is the top-level node for the code in question. Optional second argument is why it can't be converted. """

        lineno = node.get_lineno()
        self.log_message("Line %d: %s" % (lineno, reason))