I run a thread that backs the db up every X hours with
FBBackupManager.backupDatabase(), and each time before backing up, it
calls FBBackupManager.setBackupPath(path) ('path' might or might not
differ from the previous backup path).
I got the following error:

java.lang.IllegalArgumentException: You cannot use
setBackupPath(String) and addBackupPath(String, int) methods
simultaneously.
at
org.firebirdsql.management.FBBackupManager.addBackupPath(FBBackupManager.java:162)
at
org.firebirdsql.management.FBBackupManager.setBackupPath(FBBackupManager.java:151)
at
...mycode...

Should I produce a test case or is this enough?

Cheers,
John