anchor.diff:     * same builder object. For convenience `nest` can also be a string or another
      * common object that will be converted to a string and added as a text node.
      *
  -   * For example, to generate _&lt;message>Hello World&lt;/message>_ one would write:
  +   * For example, to generate an element with the tag _message_ and the contained
  +   * text _Hello World_ one would write:
      *
      *     builder.element('message', nest: 'Hello World');
      *
  -   * To add multiple child elements as in _&lt;message>Hello
  -   * World&lt;break />&lt;/message>_ one would write:
  +   * To add multiple child elements as in one would use the argument [nest]:
      *
      *     builder.element('message', nest: () {
      *       builder..text('Hello World')
  
positive.code:    * [namespace] URI is provided, the prefix is looked up, verified and
     * combined with the given attribute [name].
     *
     * To generate _&lt;message lang="en" />_ one would write:
     *
     *     builder.element('node', nest: () {
     *        builder.attribute('lang', 'en');
     *     });
     *
  
negative.code:   /**
     * Adds a [XmlProcessing] node with the provided [target] and [text].
     *
     * For example, to generate a processing element with the _xml_ and the
     * attribute _version="1.0"_ one would write:
     *
     *     builder.processing('xml', 'version="1.0"');
     *
  