# File lib/fog/rackspace/requests/storage/head_object.rb, line 24
        def head_object(container, object)
          c = mock_container! container
          o = c.mock_object! object

          headers = o.to_headers

          hashes, length = [], 0
          o.each_part do |part|
            hashes << part.hash
            length += part.bytes_used
          end

          headers['Etag'] = "\"#{Digest::MD5.hexdigest(hashes.join)}\""
          headers['Content-Length'] = length.to_s
          headers['X-Static-Large-Object'] = "True" if o.static_manifest?

          response = Excon::Response.new
          response.status = 200
          response.headers = headers
          response
        end