docs: function mergeObjects (o1, o2) {
    let m = Object.assign({}, o1)
    for (let attr in o2) {
      let v = o2[attr]
  
      if (attr in m && isPlainObject(v) && isPlainObject(m[attr]))
        m[attr] = mergeObjects(m[attr], v)
      else
        m[attr] = v
    }
    return m
  }