title: why doesn't TextNode have update value(set) method?
body: <p>I want to modify the value of a <code>TextNode</code> using jackson.<br>
  But there is no such method in the API.<br>
  Then I try to use reflection to overcome the limitation:  </p>
  
  <pre><code>public class TestModify {
  
      public static void main(final String[] args) throws JsonProcessingException, IOException,
              NoSuchFieldException, SecurityException, IllegalArgumentException,
              IllegalAccessException {
          final String json = "[{},\"123123\",\"12456\"]";
          final ObjectMapper mapper = new ObjectMapper();
          final JsonNode node = mapper.readTree(json);
          final Iterator&lt;JsonNode&gt; nodes = node.elements();
          while (nodes.hasNext()) {
              final JsonNode n = nodes.next();
              if (n instanceof TextNode) {
                  final Field f = TextNode.class.getDeclaredField("_value");
                  f.setAccessible(true);
                  f.set(n, "updated");
              }
              System.out.println(n.getClass());
          }
          System.out.println(node);
      }
  }  
  </code></pre>
  
  <p>The code seems to work fine and <code>println</code> shows:</p>
  
  <pre><code>class com.fasterxml.jackson.databind.node.ObjectNode
  class com.fasterxml.jackson.databind.node.TextNode
  class com.fasterxml.jackson.databind.node.TextNode
  [{},"updated","updated"]   
  </code></pre>
  
  <p>So why is there no update method in the original API?</p>