@CanIgnoreReturnValue
    public Builder allowMissingExpiration() {
      this.allowMissingExpiration = true;
      return this;
    }
When set, the validator accepts tokens that do not have an expiration set.

<p>In most cases, tokens should always have an expiration, so this option should rarely be
used.
java_src/src/main/java/com/google/crypto/tink/jwt/JwtValidator.java