You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: provider.rb
    path of file: ./repos/sinatra-rest-api/lib/sinatra-rest-api
    
    the code of the file until where you have to start completion: module Sinatra
  module RestApi
    # Prodiver
    class Provider
      OPTIONS = [ :actions, :include, :plural, :singular ].freeze
      REQUEST = {
        # content_types: [ :formdata, :json, :multipart, :www_form ]
     
    
      def initialize( klass, opts, app, &block )
        @klass = klass
        @options = opts
        @app = app
        instance_eval( &block ) if block_given?
        init_settings
        @adapter = Adapter.new( self )
        @router = Router.new( self )
        @router.generate_routes
        klass_name = klass.to_s.split( '::' ).last
        @@klasses[klass_name] = { class: klass, model_singular: @adapter.model_singular }
        decorate_model
      end