static public async Task ActAsync(TargetSpaceCtx ctx)
    {
        // add 1 presence in target land even if you normally could not due to land type.
        await ctx.PlacePresenceHere();

        // Defend 20
        ctx.Defend(20);

        // if you have 2 sun, 3 earth,
        if (await ctx.YouHave("2 sun,3 earth"))
        {
            // 3 fear if invaders are present,
            if (ctx.HasInvaders)
            {
                ctx.AddFear(3);
            }

            // Invaders skip all actions in target land this turn.
            ctx.SkipAllInvaderActions();
        }
    }