old_contents: 'use strict';
  
  /**
   * Internal dependencies
   */
  let SampleProportion = require( './sample-proportion' );
  
  function Variation( name, color, participants, conversions ) {
  	this.name = name;
  	this.color = color;
  	this.participants = participants;
  	this.conversions = conversions;
  	this.proportion = new SampleProportion( participants, conversions );
  }
  
  // See: http://blog.42floors.com/math-split-testing-part-2-chance-better/
  Variation.prototype.isGaussian = function() {
  	let np = this.participants * this.proportion.mean,
  		nq = this.participants * ( 1 - this.proportion.mean );
  
  	return this.participants >= 30 && np >= 5 && nq >= 5;
  };
  
  module.exports = Variation;
  
new_contents: 'use strict';
  
  /**
   * Internal dependencies
   */
  let SampleProportion = require( './sample-proportion' );
  
  class Variation {
  	constructor( name, color, participants, conversions ) {
  		this.name = name;
  		this.color = color;
  		this.participants = participants;
  		this.conversions = conversions;
  		this.proportion = new SampleProportion( participants, conversions );
  	}
  
  	// See: http://blog.42floors.com/math-split-testing-part-2-chance-better/
  	isGaussian() {
  		let np = this.participants * this.proportion.mean,
  			nq = this.participants * ( 1 - this.proportion.mean );
  
  		return this.participants >= 30 && np >= 5 && nq >= 5;
  	};
  }
  
  module.exports = Variation;
  
subject: Convert Variation class to ES6