def experiment(id)
      @url = "experiments/#{id}"
      raise OptimizelyError::NoExperimentID, "An Experiment ID is required to retrieve the experiment." if id.nil?

      response = self.get(@url)
      Experiment.new(response)
    end
def experiment(id)
      @url = "experiments/#{id}"
      raise OptimizelyError::NoExperimentID, "An Experiment ID is required to retrieve the experiment." if id.nil?

      response = self.get(@url)
      Experiment.new(response)
    end
Returns the details for a specific experiment.

 == Usage
  optimizely = Optimizely.new({ api_token: 'oauth2_token' })
  experiment = optimizely.experiment(12345) # Look up the experiment.