final boolean cancelTimeout() {
        final ScheduledFuture<?> timeoutFuture = this.timeoutFuture;
        if (timeoutFuture == null) {
            return true;
        }

        this.timeoutFuture = null;
        return timeoutFuture.cancel(false);
    }
Writes the {@link HttpHeaders trailers} to the {@link Channel}.
Note that the written data is not flushed by this method. The caller should explicitly call
{@link Channel#flush()} when each write unit is done.
core/src/main/java/com/linecorp/armeria/client/AbstractHttpRequestHandler.java