public function button($title = null, array $options = array())
{
$defaults = array('escape' => true);
list($scope, $options) = $this->_options($defaults, $options);
list($title, $options, $template) = $this->_defaults(__METHOD__, $title, $options);
$arguments = compact('type', 'title', 'options', 'value');
return $this->_render(__METHOD__, 'button', $arguments, $scope);
}