code: function ProcessingInstruction(doc, name, content) {
      if (!doc) {
          throw new Error('document argument required');
      } else if (! (doc instanceof bindings.Document)) {
          throw new Error('document argument must be an ' +
                          'instance of Document');
      } else if (!name) {
          throw new Error('name argument required');
      }
  
      return new bindings.ProcessingInstruction(doc, name, content);
  }
docs: / create a new processing instruction on the given document / @param doc the Document to create the processing instruction for / @param name the processing instruction name / @param {String} [content] processing instruction content / @constructor