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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 gecos(self):
 """Force double quoted gecos. returns: str: The double quoted gecos. """

        if not self._gecos:
            return None
        if self._gecos.startswith(text_type('\'')) and self._gecos.endswith(text_type('\'')):
            self._gecos = '\"{0}\"'.format(self._gecos[1:-1])
            return self._gecos
        elif self._gecos.startswith(text_type('\"')) and self._gecos.endswith(text_type('\"')):
            return self._gecos
        else:
            return '\"{0}\"'.format(self._gecos)