@marcj I played with the new sortable implementation with multi scopes...

when changing the schema to 
`xml
	<table name="sortable_multi_scopes">
		<column name="id" required="true" primaryKey="true" autoIncrement="true" type="INTEGER" />
		<column name="category_id" required="true" type="INTEGER" />
		<column name="sub_category_id" type="INTEGER" />
		<column name="title" type="VARCHAR" size="100" primaryString="true" />
		<column name="position" type="INTEGER" />
		<behavior name="sortable">
			<parameter name="rank_column" value="position" />
			<parameter name="use_scope" value="true" />
			<parameter name="scope_column" value="sub_category_id, category_id" />
		</behavior>
	</table>
`

it generates methods like 

`php
    /**
     * Returns the objects in a certain list, from the list scope
     *
     * @param     int $scopeSubCategoryId Scope value for column `SubCategoryId`
     * @param     int $scopeCategoryId Scope value for column `CategoryId`
     *
     * @return SortableMultiScopesQuery The current query, for fluid interface
     */
    public function inList($scopeSubCategoryId = null, $scopeCategoryId)
`

here we have a problem, because the first arg is optional and the second is required.

2 possible solutions:
a) the behavior re-sorts the parameters from required to optional
b) we add a warning to the docs and tell the user that he needs to define the multi-scope parameter in a proper order