@NonNull
  public static Caffeine<Object, Object> from(String spec) {
    return from(CaffeineSpec.parse(spec));
  }
@ NonNull public static Caffeine < Object , Object > from ( String spec ) { return from ( CaffeineSpec . parse ( spec ) ) ; }
Constructs a new {@code Caffeine} instance with the settings specified in {@code spec}.

@param spec a String in the format specified by {@link CaffeineSpec}
@return a new instance with the specification's settings