Howto stop Net::HTTP.post_form from autoencoding parameters
===

I'm trying to test the functionality of a webservice using ruby with minitest and Net:HTTP.

This code

    class TestOne <  MiniTest::Unit::TestCase
    
    load 'test/test_helper.rb'
    
    	def test_one
    
    		xml_to_transmit = "
    <?xml version='1.0' encoding='UTF-8' ?>
    <MyRequest version='1.0'>
    	<Id>1</Id>
    </MyRequest>"
    
    		url = URI('http://example.com/api')
    		resp, data = Net::HTTP.post_form(url,nil => xml_to_transmit)
    	end
    end

will escape the xml that I'm trying to send to the server as a parameter. Is there a way to send it unescaped? (I have no possibility to change the serverside code.)

This is the parameter as it is received by the server

    =%0A%3C%3Fxml+version%3D%271.0%27+encoding%3D%27UTF-8%27+%3F%3E%0A%3CMyRequest+version%3D%271.0%27%3E%0A%09%3CId%3E1%3C%2FId%3E%0A%3C%2FMyRequest%3E

My test_helper.rb is quite basic

    require 'minitest/unit'
    require 'minitest/autorun' 
    require 'net/http'

Does anyone have any ideas on why this is happening and what I could do about it?