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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 has_option(self, section, option):
 """Check for the existence of a given option in a given section. If the specified `section' is None or an empty string, DEFAULT is assumed. If the specified `section' does not exist, returns False."""

        if not section or section == self.default_section:
            option = self.optionxform(option)
            return option in self._defaults
        elif section not in self._sections:
            return False
        else:
            option = self.optionxform(option)
            return (option in self._sections[section]
                    or option in self._defaults)