Write the appropriate python code in order to download a given stock the finance yahoo website for the ticker of BIST100 stocks. For example, the ticker for Sabanci Holding stock is SAHOL.IS, hence the user enters the ticker ID of the stock and your python function downloads the daily stock prices of the stock and calculate the mean and volatility of daily log-returns for the last one year. The user enters the ticker id, start and end date of the stock price to be downloaded. Then your function returns the mean, volatility of the returns and creates a plot of the close prices of the stock for the given time period.