How do I use ThreadLocalTargetSource in a TaskDecorator?

Question

We are using Spring's ThreadLocalTargetSource to set some Tenant context information into a bean and propagate it through a typical HTTP request or received event. The approach is similar to what is described in:

https://dzone.com/articles/an-alternative-approach-to-threadlocal-using-sprin-1

@Bean(destroyMethod = "destroy")
public ThreadLocalTargetSource threadLocalTenantContext() {
    ThreadLocalTargetSource result = new ThreadLocalTargetSource();
    result.setTargetBeanName("tenantContext");
    return result;
}

@Primary
@Bean(name = "proxiedThreadLocalTargetSource")
public ProxyFactoryBean proxiedThreadLocalTargetSource(ThreadLocalTargetSource threadLocalTargetSource) {
    ProxyFactoryBean result = new ProxyFactoryBean();
    result.setTargetSource(threadLocalTargetSource);
    return result;
}

However, I now need to use a TaskExecutor to run some process asynchronously and I'm not sure how to send that tenant information into the newly spawned threads. Using TaskDecorator it would be simple to get information from MDC into the new thread:

// Set this in taskExecutor.setDecorator(...)
public class TenantContextThreadDecorator implements TaskDecorator {

    @Override
    public Runnable decorate(Runnable runnable) {
        final Map<String, String> mdc = MDC.getCopyOfContextMap();
        return () -> {
            try {
                MDC.setContextMap(mdc);
                runnable.run();
            } finally {
                MDC.clear();
            }
        };
    }
}

But I have no idea how to get the TenantContext to set that on the runnable.