.weakKeys()
            .softValues()
            .expireAfterWrite(15L, SECONDS);
    assertCacheBuilderEquivalence(expected, CacheBuilder.from(spec));
  }

  public void testParse_unknownKey() {
    assertThrows(IllegalArgumentException.class, () -> parse("foo=17"));
  }

  public void testParse_extraCommaIsInvalid() {
    assertThrows(IllegalArgumentException.class, () -> parse("weakKeys,"));