def variations(experiment_id)
      raise OptimizelyError::NoExperimentID, "An Experiment ID is required to retrieve variations." if experiment_id.nil?

      response = self.get("experiments/#{experiment_id}/variations")
      response.collect { |variation_json| Variation.new(variation_json) }
    end
def variations(experiment_id)
      raise OptimizelyError::NoExperimentID, "An Experiment ID is required to retrieve variations." if experiment_id.nil?

      response = self.get("experiments/#{experiment_id}/variations")
      response.collect { |variation_json| Variation.new(variation_json) }
    end
Returns the list of variations for a specified experiment.

 == Usage
  optimizely = Optimizely.new({ api_token: 'oauth2_token' })
  variations = optimizely.variations(12345) # Look up all variations for an experiment.