code: function(obj, keys) {
      return keys.reduce(function(memo, key) {
        if (obj[key] !== undefined) {
          memo[key] = obj[key];
        }
  
        return memo;
      }, {});
    }
docs: Return a copy of an object with only the picked keys
  
  @param {Object} obj
  @param {Array} keys
  @return {Object}