Hello Konstantin,
you could add the Interface /SAPSRM/IF_CH_WD_MAP_FACTORY to the interface tab from your specific class...
But methods from this class are public, so if you need the interface methods only once in one of your specific methods, just call the static method /SAPSRM/IF_CH_WD_MAP_FACTORY~GET_INSTANCE from /SAPSRM/CL_CH_WD_MAP_FACTORY class: in this way, you have the factory interface data.
Regards.
Laurent.