```ruby
class GenomerPluginSimple < Genomer::Plugin

  def run
    case arguments.shift
    when nil           then 'Plugin "simple" called'
    when 'echo'        then @arguments.unshift('Echo:').join(' ')
    when 'describe'    then "The scaffold contains #{scaffold.length} entries"
    when 'annotations' then annotations.inject("##gff-version 3\n"){|s, a| s << a.to_s}
    end
  end

end
```

Refactor echo arg for clarity in simple-plugin
user
```ruby
class GenomerPluginSimple < Genomer::Plugin

  def run
    case arguments.shift
    when nil           then 'Plugin "simple" called'
    when 'echo'        then "Echo: #{arguments.join(' ')}"
    when 'describe'    then "The scaffold contains #{scaffold.length} entries"
    when 'annotations' then annotations.inject("##gff-version 3\n"){|s, a| s << a.to_s}
    end
  end

end
```
assistant