code: def setup(self):
      self._alert = get_alert(context={"this_context": "that_value"})
      self._descriptor = "some_descriptor"
      self._output = "demisto"
  
imports: from mock import patch
  from nose.tools import assert_true, assert_equal, assert_false
  from streamalert.alert_processor.helpers import _assemble_alert_publisher_for_output
  from streamalert.shared.publisher import AlertPublisherRepository, AlertPublisher, CompositePublisher, DefaultPublisher, Register, WrappedFunctionPublisher
  from tests.unit.streamalert.alert_processor.helpers import get_alert
label_desc: Use image node_id 1 for calling the TestAlertPublisherRepositoryAssemblePublisher obj's underlying member method code with example usage: obj.setup() without return types