code: function extractRadioDecoders(devices) {
    var radioDecoders = {};
  
    for(var deviceId in devices) {
      var radioDecodings = devices[deviceId].radioDecodings || [];
      for(var cDecoding = 0; cDecoding < radioDecodings.length; cDecoding++) {
        var radioDecoder = radioDecodings[cDecoding].identifier;
        var radioDecoderId = radioDecoder.value;
        radioDecoders[radioDecoderId] = { identifier: radioDecoder };
      }
    }
  
    return radioDecoders;
  }
docs: Extract the radio decoders from the given list of devices.
  @param {Object} devices The given devices.