```ruby
# This is mostly copied from the Spree Zone methods,
# with added support for zipcode zone members
Spree::Zone.class_eval do

  # Check for whether an address.zipcode is available
  def include?(address)
    return false unless address
    
    members.any? do |zone_member|
      case zone_member.zoneable_type
      when "Spree::Country"
        zone_member.zoneable_id == address.country_id
      when "Spree::State"
        zone_member == address.state_id
      when "Spree::ZipCode"
        zone_member.zoneable.name == address.zipcode
      else
        false
      end
    end
  end

  def zip_code_ids
    if kind == 'zip_code'
      members.collect(&:zoneable_id)
    else
      []
    end
  end

  def zip_code_ids=(ids)
    zone_members.destroy_all
    ids.reject{ |id| id.blank? }.map do |id|
      member = Spree::ZoneMember.new
      member.zoneable_type = 'Spree::ZipCode'
      member.zoneable_id = id
      members << member
    end
  end

  def self.match(address)
    return unless matches = self.includes(:zone_members).
      order('zone_members_count', 'created_at').
      select { |zone| zone.include? address }

    ['zip_code', 'state', 'country'].each do |zone_kind|
      if match = matches.detect { |zone| zone_kind == zone.kind }
        return match
      end
    end
    matches.first
  end

end # Zone```

Speed up eager loading of zip codes
user
```ruby
# This is mostly copied from the Spree Zone methods,
# with added support for zipcode zone members
Spree::Zone.class_eval do

  # Check for whether an address.zipcode is available
  def include?(address)
    return false unless address
    
    members.any? do |zone_member|
      case zone_member.zoneable_type
      when "Spree::Country"
        zone_member.zoneable_id == address.country_id
      when "Spree::State"
        zone_member == address.state_id
      when "Spree::ZipCode"
        zone_member.zoneable.name == address.zipcode
      else
        false
      end
    end
  end

  def zip_code_ids
    if kind == 'zip_code'
      members.collect(&:zoneable_id)
    else
      []
    end
  end

  def zip_code_ids=(ids)
    zone_members.destroy_all
    ids.reject{ |id| id.blank? }.map do |id|
      member = Spree::ZoneMember.new
      member.zoneable_type = 'Spree::ZipCode'
      member.zoneable_id = id
      members << member
    end
  end

  def self.match(address)
    return unless matches = self.includes(zone_members: :zoneable).
      order('zone_members_count', 'created_at').
      select { |zone| zone.include? address }

    ['zip_code', 'state', 'country'].each do |zone_kind|
      if match = matches.detect { |zone| zone_kind == zone.kind }
        return match
      end
    end
    matches.first
  end

end # Zone
```
assistant