def __contains__(self, item):
        """Return item in self."""

        if isinstance(item, int):
            return self.__first <= item and item < self.__first+self.__count
        else:
            return False
def __contains__ ( self , item ) : if isinstance ( item , int ) : return self . __first <= item and item < self . __first + self . __count else : return False
Return item in self.