def __init__(self, fields=None, default=None):
        self.fields = {}
        self.subfields = {}
        self.default = default

        fields = fields or {}
        if fields is True:
            fields = {'ALL': None}
        if not isinstance(fields, dict):
            fields = dict([(v, None) for v in fields])
        for field, value in fields.items():
            try:
                fieldname, subfield = field.split('__', 1)
                self.subfields.setdefault(fieldname, {})[subfield] = value
            except __HOLE__:
                self.fields[field] = value
dataset/ETHPy150Open gregmuellegger/django-autofixture/autofixture/base.py/Link.__init__