def aggregateDf(df, timestampCol, tsRollup=True):
    """
    Utility function to aggregate dataframe on timestamp column
    """
    df.dropna(inplace=True)
    if tsRollup:
        df = df.groupby(timestampCol).sum()
        df.reset_index(inplace=True)
    df.columns = ["ds" if col == timestampCol else "y" for col in df.columns]
    return df