boolean cacheable() {
            return cacheable;
        }
Closes all the resources allocated and used by this resolver.

<p>Please note that this method does not clear the {@link CacheEntry} because the
{@link #addressResolverCache} is created by {@link RefreshingAddressResolverGroup} and shared across
from all {@link RefreshingAddressResolver}s. {@link CacheEntry} is cleared when
{@link RefreshingAddressResolverGroup#close()} is called.
core/src/main/java/com/linecorp/armeria/client/RefreshingAddressResolver.java