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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(self, section, option, default=None):
 """Get a parameter value and return a string. If default is specified and section or option are not defined in the file, they are created and set to default, which is then the return value. """

        with self._lock:
            if not self._config.has_option(section, option):
                if default is not None:
                    self._set(section, option, default)
                return default
            return self._config.get(section, option)