'Returns a list of assets for the current date, as defined by the
fetcher data.
Returns
list: a list of Asset objects.'

def get_fetcher_assets(self, dt):

    if (self._extra_source_df is None):
        return []
    day = normalize_date(dt)
    if (day in self._extra_source_df.index):
        assets = self._extra_source_df.loc[day]['sid']
    else:
        return []
    if isinstance(assets, pd.Series):
        return [x for x in assets if isinstance(x, Asset)]
    else:
        return ([assets] if isinstance(assets, Asset) else [])
