'``date_styles`` is a list of ``StorageStyle``s to store and
retrieve the whole date from. The ``year`` option is an
additional list of fallback styles for the year. The year is
always set on this style, but is only retrieved if the main
storage styles do not return a value.'

def __init__(self, *date_styles, **kwargs):

    super(DateField, self).__init__(*date_styles)
    year_style = kwargs.get('year', None)
    if year_style:
        self._year_field = MediaField(*year_style)
