@Override
        public ByteBufAllocator alloc() {
            return alloc;
        }
Sets the specified {@code timedOut}. If the specified {@code timedOut} is {@code true},
{@link RequestContext#isTimedOut()} will always return {@code true}.
This is useful for checking the behavior of a {@link Service} and {@link Client}
when a request exceeds a deadline.
core/src/main/java/com/linecorp/armeria/common/AbstractRequestContextBuilder.java