```ruby
module BorderPatrol
  class InsufficientPointsToActuallyFormAPolygonError < ArgumentError; end
  class Point < Struct.new(:x, :y); end

  def self.parse_kml(string)
    doc = Nokogiri::XML(string)
    polygons = doc.xpath('//kml:Polygon', 'kml' => 'http://earth.google.com/kml/2.2').map do |polygon_kml|
      parse_kml_polygon_data(polygon_kml.to_s)
    end
    BorderPatrol::Region.new(polygons)
  end

  private
  def self.parse_kml_polygon_data(string)
    doc = Nokogiri::XML(string)
    coordinates = doc.xpath("//coordinates").text.strip.split("\n")
    points = coordinates.map do |coord|
      x, y, z = coord.strip.split(',')
      BorderPatrol::Point.new(x.to_f, y.to_f)
    end
    BorderPatrol::Polygon.new(points)
  end
end

require 'set'
require 'nokogiri'
require 'border_patrol/polygon.rb'
require 'border_patrol/region.rb'
```

Remove '.rb' when requiring files
user
```ruby
module BorderPatrol
  class InsufficientPointsToActuallyFormAPolygonError < ArgumentError; end
  class Point < Struct.new(:x, :y); end

  def self.parse_kml(string)
    doc = Nokogiri::XML(string)
    polygons = doc.xpath('//kml:Polygon', 'kml' => 'http://earth.google.com/kml/2.2').map do |polygon_kml|
      parse_kml_polygon_data(polygon_kml.to_s)
    end
    BorderPatrol::Region.new(polygons)
  end

  private
  def self.parse_kml_polygon_data(string)
    doc = Nokogiri::XML(string)
    coordinates = doc.xpath("//coordinates").text.strip.split("\n")
    points = coordinates.map do |coord|
      x, y, z = coord.strip.split(',')
      BorderPatrol::Point.new(x.to_f, y.to_f)
    end
    BorderPatrol::Polygon.new(points)
  end
end

require 'set'
require 'nokogiri'
require 'border_patrol/polygon'
require 'border_patrol/region'
```
assistant