code: @NonNull
    public static Caffeine<Object, Object> from(String spec) {
      return from(CaffeineSpec.parse(spec));
    }
docs: 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