code: function normalizeAttributes (attributes) {
    let mainAttributes = []
    let maxValue
  
    for (let key in attributes) {
      if (validAttributes.indexOf(key) === -1) {
        continue
      }
  
      if (!maxValue || attributes[key] > maxValue) {
        maxValue = attributes[key]
        mainAttributes = [key]
      } else if (attributes[key] === maxValue) {
        mainAttributes.push(key)
      }
    }
  
    let secondaryAttributes = Object.keys(attributes).filter(a =>
      mainAttributes.indexOf(a) === -1 &&
      validAttributes.indexOf(a) !== -1
    )
    return [mainAttributes, secondaryAttributes]
  }
docs: Get a representation showing the the major and minor attributes of an item {Precision: 85, Power: 126, Ferocity: 85} -> [['Power'], ['Precision', 'Ferocity']]