https://airflow.apache.org/docs/apache-airflow/stable/configurations-ref.html#store-dag-code

![Captura de pantalla 2021-05-26 a las 17 47 56](https://user-images.githubusercontent.com/11339132/119691160-a2049a00-be4a-11eb-8f55-0ad2c6117620.png)

The Default is True or None?
tests/core/test_configuration.py
cfg_dict = conf.as_dict()
        
        assert cfg_dict['core']['unit_test_mode'] == 'True'
        assert cfg_dict['core']['percent'] == 'with%inside'
        
        assert cfg_dict['testsection']['testkey'] == '< hidden >'
        assert cfg_dict['kubernetes_environment_variables']['AIRFLOW__TESTSECTION__TESTKEY'] == '< hidden >'
    def test_conf_as_dict_source(self):
        
        cfg_dict = conf.as_dict(display_source=True)
        assert cfg_dict['core']['load_examples'][1] == 'airflow.cfg'
        assert cfg_dict['core']['load_default_connections'][1] == 'airflow.cfg'
        assert cfg_dict['testsection']['testkey'] == ('< hidden >', 'env var')
    def test_conf_as_dict_sensitive(self):
        
        cfg_dict = conf.as_dict(display_sensitive=True)
        assert cfg_dict['testsection']['testkey'] == 'testvalue'
        assert cfg_dict['testsection']['testpercent'] == 'with%percent'
        
        cfg_dict = conf.as_dict(display_sensitive=True, display_source=True)
        assert cfg_dict['testsection']['testkey'] == ('testvalue', 'env var')
    @conf_vars({("core", "percent"): "with%%inside"})
    def test_conf_as_dict_raw(self):
        
        cfg_dict = conf.as_dict(raw=True, display_sensitive=True)
        assert cfg_dict['testsection']['testkey'] == 'testvalue'
        
        assert cfg_dict['testsection']['testpercent'] == 'with%%percent'
        assert cfg_dict['core']['percent'] == 'with%%inside'
    def test_conf_as_dict_exclude_env(self):