code: function _doesEventContainsNestedStackId(stack) {
      if (stack.ResourceType !== 'AWS::CloudFormation::Stack') {
          return false;
      }
      if (stack.ResourceStatusReason !== 'Resource creation Initiated') {
          return false;
      }
      if (stack.ResourceStatus !== 'CREATE_IN_PROGRESS') {
          return false;
      }
      if (_.isNil(stack.PhysicalResourceId)) {
          return false;
      }
  
      return _hasLabelNestedStackName(stack.PhysicalResourceId);
  }
docs: Check if the stack event contains the name a Nested Stack name.
  @param stack The StackEvent object.
  @returns {boolean} true if the object contain a Nested Stack name, false otherwise.
  @private