+import org.eclipse.tracecompass.statesystem.core.ITmfStateSystem;
+import org.eclipse.tracecompass.statesystem.core.exceptions.AttributeNotFoundException;
+import org.eclipse.tracecompass.statesystem.core.exceptions.StateSystemDisposedException;
+import org.eclipse.tracecompass.statesystem.core.interval.ITmfStateInterval;