Make Task::copyTo not abstract

[vlaaad]

This is clearly annoying to have to override method if it wont be used.

[davebaol]

Yes but with a void implementation you will likely forget to implement it, which can be somewhat hard to debug.
If the abstract copyTo is so annoying for you, just create a concrete MyLeafTask class that extends LeafTask and use it as the superclass of all your leaf nodes. 😉