```ruby
# encoding: UTF-8

require 'gooddata'

require File.join(File.dirname(__FILE__), 'base_middleware')

module GoodData::Bricks
  class RestForceMiddleware < GoodData::Bricks::Middleware
    def call(params)
      username = params[:salesforce_username]
      password = params[:salesforce_password]
      token = params[:salesforce_token]
      client_id = params[:salesforce_client_id]
      client_secret = params[:salesforce_client_secret]
      oauth_token = params[:salesforce_oauth_token]
      refresh_token = params[:salesforce_refresh_token]
      host = params[:salesforce_host]

      credentials = {}

      credentials = if (username && password && token)
                      {
                        :username => username,
                        :password => password,
                        :security_token => token
                      }
                    elsif (oauth_token && refresh_token)
                      {
                        :oauth_token => oauth_token,
                        :refresh_token => refresh_token
                      }
                    end

      client = if credentials
                 credentials.merge!({
                                      :client_id => client_id,
                                      :client_secret => client_secret,
                                    })
                 credentials[:host] = host unless host.nil?

                 Restforce.log = true if params[:salesforce_client_logger]
                 Restforce.new(credentials)
               end
      @app.call(params.merge(:salesforce_client => client))
    end
  end
end```

Remove empty and not used initializer
user
```ruby
# encoding: UTF-8

require 'gooddata'

require File.join(File.dirname(__FILE__), 'base_middleware')

module GoodData::Bricks
  class RestForceMiddleware < GoodData::Bricks::Middleware
    def call(params)
      username = params[:salesforce_username]
      password = params[:salesforce_password]
      token = params[:salesforce_token]
      client_id = params[:salesforce_client_id]
      client_secret = params[:salesforce_client_secret]
      oauth_token = params[:salesforce_oauth_token]
      refresh_token = params[:salesforce_refresh_token]
      host = params[:salesforce_host]

      credentials = if (username && password && token)
                      {
                        :username => username,
                        :password => password,
                        :security_token => token
                      }
                    elsif (oauth_token && refresh_token)
                      {
                        :oauth_token => oauth_token,
                        :refresh_token => refresh_token
                      }
                    end

      client = if credentials
                 credentials.merge!({
                                      :client_id => client_id,
                                      :client_secret => client_secret,
                                    })
                 credentials[:host] = host unless host.nil?

                 Restforce.log = true if params[:salesforce_client_logger]
                 Restforce.new(credentials)
               end
      @app.call(params.merge(:salesforce_client => client))
    end
  end
end```
assistant