code: function(projectConfig, experimentKey) {
      var experiment = projectConfig.experimentKeyMap[experimentKey];
      if (fns.isEmpty(experiment)) {
        throw new Error(sprintf(ERROR_MESSAGES.INVALID_EXPERIMENT_KEY, MODULE_NAME, experimentKey));
      }
      return experiment.trafficAllocation;
    }
docs: Given an experiment key, returns the traffic allocation within that experiment
  @param  {Object} projectConfig Object representing project configuration
  @param  {string} experimentKey Key representing the experiment
  @return {Array<Object>}        Traffic allocation for the experiment
  @throws If experiment key is not in datafile