You are faced with a task similar to the previous one: convert data to stationary. You will remove seasonality in the Seasonality Time Series.csv dataset using the difference method. Track a certain amount of time for which the time pattern repeats and use the difference method:

1. Read the dataset.
2. Analyze how long patterns repeat (visualize "Var" and "Date" columns of the df DataFrame in this order).
3. Use the resulting number (it is 8) for the difference method. Perform the differentiation for the "Var" column. Save the obtained result within the df_diff variable.
4. Visualize the transformed data.