be aware of: If listener contract will be changed - analize carefully all fired events
Some pices of code based on reflection and invocation, so
NoSuchMethodException may occures.(It's implementation pitfalls)
pumpingStateChange(String id) This property was separate from pumping update because it's describe pumping as process
and in pumping update - notify that pumping was changed as entity.
void
pumpingUpdate(String id) notification that pumping was update means that some pice of bytes downloaded
or some meta data such as real url, output file name obtain from server.
void
pumpsInvoke() notification that downloader invoked work.
void
pumpsTerminate() notification that downloader stoped work.
This property was separate from pumping update because it's describe pumping as process
and in pumping update - notify that pumping was changed as entity.