Set a section. If section already exists, overwrite the old one.

def set_section(self, section):
        """Set a section. If section already exists, overwrite the old one.
        """
        if not isinstance(section, Section):
            raise Exception("You")

        try:
            self.remove_section(section.name)
        except:
            pass

        self._sections[section.name] = copy.deepcopy(section)