Cannot deploy verticle

[afterthought]

What am I missing?

The help says:
% verticle -h deploy
usage: verticle [-h | --help] deploy [-i | --instances] [-w | --worker]

...

When I run this (where EchoChamber is my class):
verticle deploy -i 1 -w false io.cozmic.usher.EchoChamber {}

I get this error:
verticle deploy -i 1 -w false io.cozmic.usher.EchoChamber {}: exception: Invalid JSON:io.cozmic.usher.EchoChamber{}

It seems like it is combining the

and the into the same argument. I think I tried almost every combination in ordering the arguments. I've looked at the code for the VerticleCommand and cannot see any problems.

Any ideas? Thanks.