Changing Intent Ids to use explicit id assignment

Change-Id: I5a4bff87842c37a869e7691b353529eaefc929db
diff --git a/core/api/src/test/java/org/onlab/onos/net/intent/MockIdGenerator.java b/core/api/src/test/java/org/onlab/onos/net/intent/MockIdGenerator.java
new file mode 100644
index 0000000..96ecac9
--- /dev/null
+++ b/core/api/src/test/java/org/onlab/onos/net/intent/MockIdGenerator.java
@@ -0,0 +1,17 @@
+package org.onlab.onos.net.intent;
+
+import org.onlab.onos.core.IdGenerator;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * Mock id generator for testing.
+ */
+public class MockIdGenerator implements IdGenerator {
+    private AtomicLong nextId = new AtomicLong(0);
+
+    @Override
+    public long getNewId() {
+        return nextId.getAndIncrement();
+    }
+}