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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_variables(self) -> Set[str]: """Find all the variables specified in a format string. This returns a list of all the different variables specified in a format string, that is the variables inside the braces. """

        variables = set()
        for cmd in self._cmd:
            for var in self.__formatter.parse(cmd):
                logger.debug("Checking variable: %s", var)
                # creates and requires are special class values
                if var[1] is not None and var[1] not in ["creates", "requires"]:
                    variables.add(var[1])
        return variables