def load_config(provided_config = nil)
      @config = (provided_config.nil?) ?
          AdsCommon::Config.new(
              File.join(ENV['HOME'], api_config.default_config_filename)) :
          AdsCommon::Config.new(provided_config)
      init_config()
    end
def load_config(provided_config = nil)
      @config = (provided_config.nil?) ?
          AdsCommon::Config.new(
              File.join(ENV['HOME'], api_config.default_config_filename)) :
          AdsCommon::Config.new(provided_config)
      init_config()
    end
Helper method to load the default configuration file or a given config.