If we are extracting this into it's own class, we could simplify the error creation:

```ruby
# cookbook_generator
# ...
raise Berkshelf::LicenseNotFound.new(options[:license])
```

Then

```ruby
class LicenseNotFound < BerkshelfError
  status_code(134)
 

  # @param [String] license
  #   the invalid license that was supplied
  def initialize(license)
    @license = license
  end

  def to_s
    [
      "Unknown license: ''#{@license}",
      "Available licenses: #{Berkshelf::CookbookGenerator::LICENSES.join(', ') }",
    ].join("\n")
  end
end
```

This way the error is self-contained and centralized.