src/Http/Router.php
public function api($version, $second, $third = null)
	{
		if (func_num_args() == 2)
			list($version, $callback, $attributes) = array_merge(func_get_args(), [[]]);
		else
			list($version, $attributes, $callback) = func_get_args();
		$_attributes = ['prefix' => $version, 'namespace' => 'Api\\'.Str::studly($version)];
		$attributes = array_merge($_attributes, $attributes);
		$this->group($attributes, $callback);
	}
public function api($version, $second, $third = null)
	{
		if (func_num_args() == 2)
			list($version, $callback, $attributes) = array_merge(func_get_args(), [[]]);
		else
			list($version, $attributes, $callback) = func_get_args();
		$_attributes = ['prefix' => $version, 'namespace' => 'Api\\'.Str::studly($version)];
		$attributes = array_merge($_attributes, $attributes);
		$this->group($attributes, $callback);
	}
version for api
@example $router->api('v1', function($router){ });
@example this is equal: $router->group(['prefix' => 'v1', 'namespace' => 'Api\\V1'], $callback);

@param  [type]  $version  the api's version
@param  Closure $callback [description]
@return [type]            [description]