In this program, you are required to write an automatic Modern Art Generator program. The following points are specified to generate the automated modern arts.

- Use a 600 x 300 canvas for creating the artwork.

- The artwork will be a composition of rectangles.

- The rectangles will be of random sizes and at random positions.

- The rectangles will be of random colors and opacities.

- The rectangles will be of a minimum size 10x10, and a maximum size 100x100.

- All rectangles should be placed within the default visible area of 600x300.

- The artwork will be made up of a total of 50 rectangles.

Note: Use the basic Pane class to place the rectangles so that absolute object placement is allowed for the random rectangles in the artwork.