code: function(projectConfig, experimentId) {
      var experiment = projectConfig.experimentIdMap[experimentId];
      if (fns.isEmpty(experiment)) {
        throw new Error(sprintf(ERROR_MESSAGES.INVALID_EXPERIMENT_ID, MODULE_NAME, experimentId));
      }
      return experiment.layerId;
    }
docs: Get layer ID for the provided experiment key
  @param  {Object} projectConfig Object representing project configuration
  @param  {string} experimentId Experiment ID for which layer ID is to be determined
  @return {string} Layer ID corresponding to the provided experiment key
  @throws If experiment key is not in datafile