@MustBeClosed
    default SafeCloseable replace() {
        final RequestContext oldCtx = RequestContextUtil.getAndSet(this);
        return () -> RequestContextUtil.pop(this, oldCtx);
    }
Replaces the current {@link RequestContext} in the thread-local with this context without any validation.
This method also does not run any callbacks.

<p><strong>Note:</strong> Do not use this if you don't know what you are doing. This method does not
prevent the situation where a wrong {@link RequestContext} is pushed into the thread-local.
Use {@link #push()} instead.

@see ClientRequestContext#push()
@see ServiceRequestContext#push()
core/src/main/java/com/linecorp/armeria/common/RequestContext.java