def _cov(X, Y):
    return window_aggregations.ewmcov(X, start, end, min_periods, Y, self._com, self.adjust, self.ignore_na, True)
def _cov(X, Y):
    return window_aggregations.ewmcov(X, start, end, min_periods, Y, self._com, self.adjust, self.ignore_na, True)