Add a hypothetical Echo example

examples/echo/echo.mu

@@ -0,0 +1,26 @@
+// Copyright 2016 Marapongo, Inc. All rights reserved.
+
+module echo
+import mu
+
+// Echo is a simple service that wraps an API gateway and exposes a single Say function.
+service Echo {
+    ctor() {
+        new mu.APIGateway {
+            api = this
+            impl = "./mu.ts"
+            port = this.properties.port
+        }
+    }
+
+    interface {
+        // Say simply echoes back the given string.
+        Say(s: string): string
+    }
+
+    properties {
+        // port is an optional port number for the API service.
+        optional port: number = 80
+    }
+}
+

examples/echo/echo.ts

@@ -0,0 +1,23 @@
+// Copyright 2016 Marapongo, Inc. All rights reserved.
+
+import * as mu from 'mu';
+
+// Echo is a simple service that wraps an API gateway and exposes a single Say function.
+class Echo extends mu.Service {
+    constructor(
+        // port is an optional port number for the API service.
+        port: number = 80
+    ) {
+        new mu.APIGateway({
+            api: this
+            port: port
+        });
+    }
+
+    // Say simply echoes back the given string.
+    @mu.api()
+    public Say(s: string): string {
+        return s;
+    }
+}
+