@Override
    public String toString() {
        return MoreObjects.toStringHelper(this)
                          .add("context", context)
                          .toString();
    }
A base class for {@link CompletableFuture} which pushing {@link RequestContext} into the thread-local
when executes callbacks.
core/src/main/java/com/linecorp/armeria/internal/common/AbstractContextAwareFuture.java