def METHOD_NAME(df: pd.DataFrame, col: str = "y", vals: Set[Union[int, str]] = {1}) -> None:
    """Helper to check that 1 column has the same value and a case-insensitive matching name.
    We lower-case the names due to snowflake's tendency to capitalize things. This isn't ideal but it'll do for now.
    """
    df.columns = df.columns.str.lower()
    col = col.lower()
    assert isinstance(df, pd.DataFrame)
    assert df.shape == (len(vals), 1)
    assert df.columns.tolist() == [col]
    assert set(df[col]) == vals