Adding Intent Impl and shell command to install simple intent
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/UnavailableIdException.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/UnavailableIdException.java
new file mode 100644
index 0000000..fd4f122
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/UnavailableIdException.java
@@ -0,0 +1,34 @@
+package org.onlab.onos.net.intent.impl;
+
+/**
+ * Represents that there is no available IDs.
+ */
+public class UnavailableIdException extends RuntimeException {
+
+ private static final long serialVersionUID = -2287403908433720122L;
+
+ /**
+ * Constructs an exception with no message and no underlying cause.
+ */
+ public UnavailableIdException() {
+ }
+
+ /**
+ * Constructs an exception with the specified message.
+ *
+ * @param message the message describing the specific nature of the error
+ */
+ public UnavailableIdException(String message) {
+ super(message);
+ }
+
+ /**
+ * Constructs an exception with the specified message and the underlying cause.
+ *
+ * @param message the message describing the specific nature of the error
+ * @param cause the underlying cause of this error
+ */
+ public UnavailableIdException(String message, Throwable cause) {
+ super(message, cause);
+ }
+}