title: javax.json: Add new JsonNumber to existing JsonObject
body: <p>I want to add properties to an existing instance of <code>JsonObject</code>. If this property is <code>boolean</code>, this is quite easy:</p>
  
  <pre><code>JsonObject jo = ....;
  jo.put("booleanProperty", JsonValue.TRUE);
  </code></pre>
  
  <p>However, I also want to add a <code>JsonNumber</code> but I couldn't find a way to create an instance of <code>JsonNumber</code>. Here's what I could do:</p>
  
  <pre><code>JsonObjectBuilder job = Json.createObjectBuilder();
  JsonNumber jn = job.add("number", 42).build().getJsonNumber("number");
  jo.put("numberProperty", jn);
  </code></pre>
  
  <p>But I couldn't think of a more dirty way to accomplish my task. So - is there are more direct, cleaner approach to add a <code>JsonNumber</code> to an existing instance of <code>JsonObject</code>?</p>