class Geocoder::Lookup::Geoip2

def initialize
  unless configuration[:file].nil?
    begin
      @gem_name = configuration[:lib] || 'maxminddb'
      require @gem_name
    rescue LoadError
      raise "Could not load Maxmind DB dependency. To use the GeoIP2 lookup you must add the #{@gem_name} gem to your Gemfile or have it installed in your system."
    end
    @mmdb = db_class.new(configuration[:file].to_s)
  end
  super
end