class_docstr: Test shared Alert class.
docstr: Alert Class - Dynamo Key
docstr_tok: ["Alert","Class","-","Dynamo","Key"]
code: def test_dynamo_key(self):
      """Alert Class - Dynamo Key"""
      alert = self._customized_alert()
      assert_equal(
          {"RuleName": "test_rule", "AlertID": "abc-123"},
          alert.dynamo_key,
      )
  
imports: import copy
  from datetime import datetime, timedelta
  import json
  from nose.tools import assert_equal, assert_false, assert_is_instance, assert_not_in, assert_raises, assert_true
  from streamalert.shared.alert import Alert, AlertCreationError
label_desc: Use image node_id 8 for calling the TestAlert obj's underlying member method code with example usage: obj.test_dynamo_key() without return types