def merge(subtree, prefix, name, options = {})
      register(prefix, name, options)
      subtree.calls.each do |key, command|
        next unless command

        calls["#{prefix}#{key}"] = command
      end
    end
def merge(subtree, prefix, name, options = {})
      register(prefix, name, options)
      subtree.calls.each do |key, command|
        next unless command

        calls["#{prefix}#{key}"] = command
      end
    end
merge a subtree with a prefix and a name