Collect names of set properties.

        Returns:
            set: Set containing names of all properties, which are set to \
                 non-None value.

def _get_all_set_properties(self):
        """
        Collect names of set properties.

        Returns:
            set: Set containing names of all properties, which are set to \
                 non-None value.
        """
        return set(
            property_name
            for property_name in worker_mapping().keys()
            if getattr(self, property_name) is not None
        )