.. table:: :py:class:`typepy.NullString`: :py:attr:`~typepy.NullString.strict_level` = 0

    ==========================================  =========  ==========  ==========  ==========  =========
                      Method                    ``"abc"``    ``""``     ``"  "``    ``None``     ``1``  
    ==========================================  =========  ==========  ==========  ==========  =========
    :py:meth:`~.type.NullString.is_type`        ``False``  ``True``    ``True``    ``True``    ``False``
    :py:meth:`~.type.NullString.validate`       E [#f2]_   NOP [#f1]_  NOP [#f1]_  NOP [#f1]_  E [#f2]_ 
    :py:meth:`~.type.NullString.convert`        E [#f2]_   ``""``      ``""``      ``""``      E [#f2]_ 
    :py:meth:`~.type.NullString.try_convert`    ``None``   ``""``      ``""``      ``""``      ``None`` 
    :py:meth:`~.type.NullString.force_convert`  ``""``     ``""``      ``""``      ``""``      ``""``   
    ==========================================  =========  ==========  ==========  ==========  =========


.. table:: :py:class:`typepy.NullString`: :py:attr:`~typepy.NullString.strict_level` = 1

    ==========================================  =========  ==========  ==========  =========  =========
                      Method                    ``"abc"``    ``""``     ``"  "``   ``None``     ``1``  
    ==========================================  =========  ==========  ==========  =========  =========
    :py:meth:`~.type.NullString.is_type`        ``False``  ``True``    ``True``    ``False``  ``False``
    :py:meth:`~.type.NullString.validate`       E [#f2]_   NOP [#f1]_  NOP [#f1]_  E [#f2]_   E [#f2]_ 
    :py:meth:`~.type.NullString.convert`        E [#f2]_   ``""``      ``""``      E [#f2]_   E [#f2]_ 
    :py:meth:`~.type.NullString.try_convert`    ``None``   ``""``      ``""``      ``None``   ``None`` 
    :py:meth:`~.type.NullString.force_convert`  ``""``     ``""``      ``""``      ``""``     ``""``   
    ==========================================  =========  ==========  ==========  =========  =========


