class Aws::Rest::Request::Endpoint

def apply_querystring_params(uri, params)
  # collect params that are supposed to be part of the query string
  parts = @rules.shape.members.inject([]) do |prts, (member_name, member_ref)|
    if member_ref.location == 'querystring' && !params[member_name].nil?
      prts << [member_ref, params[member_name]]
    end
    prts
  end
  querystring = QuerystringBuilder.new.build(parts)
  querystring = [@query_prefix, querystring == '' ? nil : querystring].compact.join('&')
  querystring = nil if querystring == ''
  uri.query = querystring
end