def configurations
      configs = []
      bNumConfigurations.times do |config_index|
        begin
          configs << config_descriptor(config_index)
        rescue RuntimeError
          # On Windows some devices don't return it's configuration.
        end
      end
      configs
    end
def configurations
      configs = []
      bNumConfigurations.times do |config_index|
        begin
          configs << config_descriptor(config_index)
        rescue RuntimeError
          # On Windows some devices don't return it's configuration.
        end
      end
      configs
    end
Return configurations of the device.
 @return [Array<Configuration>]