BaseChannelPoolHandler - Specified cast is not valid.

[kosomgua]

Channel in BaseChannelPoolHandler throwing errors when ChannelReleased or ChannelAcquired called,
cause in this code you trying to cast from IAttribute<IdleStateTimer> to IdleStateTimer type.

       public virtual void ChannelReleased(IChannel channel)
       {
           IdleStateTimer idls = (IdleStateTimer)channel.GetAttribute(IDLE_KEY);
           idls.setIdle();
       }

       public virtual void ChannelAcquired(IChannel channel)
       {
           IdleStateTimer idls = (IdleStateTimer)channel.GetAttribute(IDLE_KEY);
           idls.setActive();
       }

Should be changed to

        public virtual void ChannelReleased(IChannel channel)
        {
            IdleStateTimer idls = channel.GetAttribute(IDLE_KEY).Get();
            idls.setIdle();
        }

        public virtual void ChannelAcquired(IChannel channel)
        {
            IdleStateTimer idls = channel.GetAttribute(IDLE_KEY).Get();
            idls.setActive();
        }