title: How to disable pretty-printing(white space/newline) in XStream?
body: <p>This is how I create XStream instance for XML:</p>
  
  <pre><code>XStream xstream = new XStream();
  </code></pre>
  
  <p>This is for JSON:</p>
  
  <pre><code>private final XStream xstream = new XStream(new JsonHierarchicalStreamDriver() {
          public HierarchicalStreamWriter createWriter(Writer writer) {
              return new JsonWriter(writer, JsonWriter.DROP_ROOT_MODE);
          }
      });
  </code></pre>
  
  <p>Both of them are pretty-printing (indenting) the output.  </p>
  
  <p>How can I ask the XStream to disable the pretty printing?</p>