class Dry::CLI::Registry::Prefix

def initialize(registry, prefix, aliases, hidden)
  @registry = registry
  @prefix   = prefix
  registry.set(prefix, nil, aliases, hidden)
end

def register(name, command = nil, aliases: [], hidden: false, &block)
  command_name = "#{prefix} #{name}"
  registry.set(command_name, command, aliases, hidden)
  if block_given?
    prefix = self.class.new(registry, command_name, aliases, hidden)
    if block.arity.zero?
      prefix.instance_eval(&block)
    else
      yield(prefix)
    end
  end
end