def METHOD_NAME(
    df: pd.DataFrame, df_preds: pd.Series, ci_lower: float, ci_upper
) -> pd.DataFrame:
    assert 0.0 <= ci_lower <= 0.5
    assert 0.5 <= ci_upper <= 1.0
    assert ci_lower != ci_upper
    df_quantiles = df.quantile(q=[ci_lower, ci_upper], axis=1).T
    df_quantiles.loc[df_quantiles[ci_lower] > df_preds, ci_lower] = df_preds
    df_quantiles.loc[df_quantiles[ci_upper] < df_preds, ci_upper] = df_preds
    return df_quantiles