How to configure cache with dynamic TTL and 1 element?

[antonywhatever]

import org.springframework.cache.interceptor.SimpleKey

val cache: Cache<SimpleKey, String> = Caffeine.newBuilder()
    .maximumSize(1)
    .build();

// use case

val token = cache.getOrLoad(
    SimpleKey.EMPTY,
    SomeValueLoaderInterfaceIHaveToImplement {
        val response = restClient.getToken()
        val value: String = response.token
        val ttl: Long = response.expiresIn
        // must return value to ttl pair
        return SomePair(token, Duration.ofSeconds(ttl))
    }
}