class WWW::Mechanize::Form

def request_data

multi-part post,
for this form, depending on if this is a regular post, get, or a
This method calculates the request data to be sent back to the server 
def request_data
  query_params = build_query()
  case @enctype.downcase
  when /^multipart\/form-data/
    boundary = rand_string(20)
    @enctype = "multipart/form-data; boundary=#{boundary}"
    params = []
    query_params.each { |k,v| params << param_to_multipart(k, v) }
    @file_uploads.each { |f| params << file_to_multipart(f) }
    params.collect { |p| "--#{boundary}\r\n#{p}" }.join('') +
      "--#{boundary}--\r\n"
  else
    WWW::Mechanize::Util.build_query_string(query_params)
  end
end