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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 listar(self):
 """List all access types. :return: Dictionary with structure: :: {‘tipo_acesso’: [{‘id’: < id >, :raise DataBaseError: Networkapi failed to access the database. :raise XMLError: Networkapi failed to generate the XML response. """

        code, map = self.submit(None, 'GET', 'tipoacesso/')

        key = 'tipo_acesso'
        return get_list_map(self.response(code, map, [key]), key)