The main responsibility of this class is to combine the different parameter sources (private navigational state,
public navigational state, interaction state, form) into the private map, public map and parameter map.
This is a port of http://svn.exoplatform.org/projects/portlet-container/branches/2.1.x/component/plugins/pc/src/main/java/org/exoplatform/services/portletcontainer/plugins/pc/aop/PortletSessionIdentityScopingCommand.java