The method is used to add user-defined mate to a Placement3D. During adding a source mate, there is done some validation to keep following rules: * If mate's logical type is UserGripPoint or UserGripPointExt, its name has to be 'G1'. * UserGripPoint is the standard handle and gets always standard matching names. * To prevent snapping on poles or holder of a bus bar system, most of source mates get the suffix '-#P#H' for matching mate names * If there are no user-defined persistent mates, EPLAN creates some transient mates. For target mates, there are no limitation with defining the mate name and the matching names.
