def b(memo, other)
      other.keys.each do |sort|
        if keys.include?(sort) && !memo.keys.include?(sort)
          memo << other.assoc(sort)
        end
      end
    end
def b(memo, other)
      other.keys.each do |sort|
        if keys.include?(sort) && !memo.keys.include?(sort)
          memo << other.assoc(sort)
        end
      end
    end
Add items from other that are common and not already added