JS: mark the EventTree as final as we no longer have pluggable implementations
JS: mark the EventTree as final as we no longer have pluggable implementations

Signed-off-by: Harvey Harrison <eadbd6b462bf3c97df0300a934c12bc2e5d1fe51@ausenco.com>

jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim