def addItemProperty(self, idd, prop):
        """Tries to add a new Property into the Item.

        @param id:
                   the ID of the new Property.
        @param prop:
                   the Property to be added and associated with the id.
        @return: C{True} if the operation succeeded, C{False} if not
        """
        # Null ids are not accepted
        if idd is None:
            raise ValueError, 'Item property id can not be null'

        # Cant add a property twice
        if idd in self._map:
            return False

        # Put the property to map
        self._map[idd] = prop
        self._list.append(idd)

        # Send event
        self.fireItemPropertySetChange()

        return True
dataset/ETHPy150Open rwl/muntjac/muntjac/data/util/propertyset_item.py/PropertysetItem.addItemProperty/original