--- /dev/null
+package org.opendaylight.controller.config.yang.test.impl;
+
+import com.google.common.base.Preconditions;
+
+public class CheckedAutoCloseable implements AutoCloseable {
+ private boolean closed = false;
+
+ @Override
+ public synchronized void close() throws Exception {
+ Preconditions.checkState(closed == false);
+ this.closed = true;
+ }
+
+ public synchronized boolean isClosed() {
+ return this.closed;
+ }
+}