to_a.join(separator)

end

def _inspect(recur_list)

def inspect

return "#<#{self.class}: {}>" if empty?

return "#<#{self.class}: {...}>" if recur_list[self.object_id]

recur_list[self.object_id] = true

ary = map { |o| o._inspect(recur_list) }

return "#<#{self.class}: {...}>" if self.__inspect_recursive?

ary = map {|o| o.inspect }

"#<#{self.class}: {#{ary.join(", ")}}>"

end

def inspect

_inspect({})

end

alias to_s inspect

def reset