```ruby
require "stash_datacite/engine"

module StashDatacite
mattr_accessor :resource_class

def self.author_class
  @@author_class.constantize
end

  class Engine < ::Rails::Engine
    isolate_namespace StashDatacite

      initializer :append_migrations do |app|
      unless app.root.to_s.match root.to_s
        config.paths["db/migrate"].expanded.each do |expanded_path|
          app.config.paths["db/migrate"] << expanded_path
        end
      end
    end

  end
end```

Load Dependencies in the Engine
user
```ruby
# http://stackoverflow.com/questions/5159607/rails-engine-gems-dependencies-how-to-load-them-into-the-application
# requires all dependencies

Gem.loaded_specs['stash_datacite'].dependencies.each do |d|
  require d.name
end

require "stash_datacite/engine"

module StashDatacite
  mattr_accessor :resource_class

  def self.author_class
    @@author_class.constantize
  end

  class Engine < ::Rails::Engine
    isolate_namespace StashDatacite

      initializer :append_migrations do |app|
      unless app.root.to_s.match root.to_s
        config.paths["db/migrate"].expanded.each do |expanded_path|
          app.config.paths["db/migrate"] << expanded_path
        end
      end
    end
  end
end```
assistant