class LRUCache::Datum

def expired?
  !@expiration.nil? && @expiration <= Time.now
end

def initialize(value, expiration, soft_expiration)
  @value = value
  @expiration = expiration
  @soft_expiration = soft_expiration
end

def soft_expired?
  !@soft_expiration.nil? && @soft_expiration <= Time.now
end