I need to write a JAVA Program without importing any of the additional libraries.

The program reads two CSV files. And concatenates them accordingly. Must only use Java libraries and NOT through any other libraries such as OPENCSV etc.

2. Manipulation methods a. Method to concatenate DataFrames. Column concatenation means stacking columns. Fruit Color Potato Tomato Plato Quantity 420 404 Potato Color Red Platato Color Fruit Potato Tomato Plato Quantity Color 420 Potato Color 404 Red 1 1 Platato Color Row concatenation means stacking rows. Fruit Potato Tomato Quantity Color 420 Potato Color 404 Red Fruit Potato 1 Quantity Color 420 Potato Color 404 Red Tomato Plato 1 Platato Color Fruit Plato Quantity Color 1 Platato Color If the combining axis doesn't match, the program should provide an error to tell Donald he made a mistake. Fruit Potato Tomato Quantity Color 420 Potato Color 404 Red X Unequal number of columns Fruit Plato Quantity Color 1 Platato Color Dead Yes