@any_form_field.register(forms.NullBooleanField)<EOL>def null_boolean_field_data(field, **kwargs):
return random.choice(['<STR_LIT:None>', '<STR_LIT:True>', '<STR_LIT:False>'])<EOL>
Return random value for NullBooleanField

>>> result = any_form_field(forms.NullBooleanField())
>>> type(result)
<type 'unicode'>
>>> result in [u'1', u'2', u'3']
True