There are unnecessary code in some classes:
1. Unnecessary class casting
2. Unused variables
3. Unused imports
4. Unnecessary checking elements of tableLabels on JComponent

It should be removed and improved.
[SQE]
  Risk: low

  There are small code improvements. No new functionality was added. Therefore running existing automatical tests and manual checking in SwingSet2 will be enough.
[SQE]