I have no idea what this means, or why it is caused. Interestingly, the code compiles and runs, although I don't know if properly as I don't know how the errors are affecting it and the rest of the example isn't covered until later in the chapter. What is causing this, how do I fix it and why does it still run with these errors?
As an aside, how do I supply a runtime argument (ie transparent, undecorated) to NetBeans? The book says via Properties -> Run : Arguments, but this does not exist.